Conference system

ABSTRACT

A conference system S includes a control unit 1 and a discussion unit 2, a running packet is repeatedly transmitted and received between both units, the running packet includes a counter flag, the control unit includes a CU communication portion 11, a CU storage portion 13, and a CU control portion 16, the discussion unit includes a DU control portion 26, the DU control portion increments the count value of the counter flag, and each time the running packet is received from the discussion unit, the CU control portion compares a count value stored in the CU storage portion and the count value of the counter flag included in the running packet received from the discussion unit.

TECHNICAL FIELD

The present invention relates to a conference system.

BACKGROUND ART

A conference system is used, for example, in an assembly or otherconference, etc., attended by a large number of participants. Theconference system is configured, for example, of a single control unit,a plurality of discussion units, connected via a communication line(wired or wireless) to the control unit, and microphones mounted on thediscussion units.

The control unit controls operations of each discussion unit andcontrols operations of the entire conference system. The discussion unitcollects the voice of a user of the discussion unit (referred tohereinafter as “user”) by means of a microphone to generate audioinformation and transmits the audio information to the control unit. Thediscussion unit is assigned to each participant.

Modes of connecting the control unit and the discussion units include aring connection mode (referred to hereinafter as “ring connection”) anda daisy chain connection mode (referred to hereinafter as “daisyconnection”) (see, for example, Non-Patent Document 1).

A ring connection is a connection mode where the discussion units areconnected to the control unit in a ring. A daisy connection is aconnection mode where the discussion units are connected sequentially ina chain to the control unit.

CITATION LIST Non-Patent Document

-   Non-Patent Document 1: “Installation and User Manual,” p. 89,    televic conference, [online], [search Feb. 9, 2016], Internet    <http://www.manualslib.com/manual/642651/Televic-Confidea.html#manual>

SUMMARY OF INVENTION Technical Problem

With a conventional conference system, there are cases where adiscussion unit or the communication line malfunctions or becomesdisconnected (such a case will be referred to hereinafter as “connectionabnormality”) during the progress of a conference. When such aconnection abnormality occurs, the number of discussion units or theconnection mode of the discussion units, as recognized by the controlunit, changes. The conventional conference system does not include afunction that reliably specifies the occurrence of a connectionabnormality, the location of occurrence of the connection abnormality,etc. The conventional conference system thus cannot continuously manageinformation, such as user information, audio information, settinginformation, etc., of each discussion unit before and after theoccurrence of a connection abnormality.

An object of the present invention is to solve the problem describedabove and to provide a conference system capable of reliably managing aconnection state of a discussion unit and a control unit andcontinuously acquiring information from the discussion unit when aconnection abnormality occurs.

Solution to Problem

The conference system according to the present invention includes acontrol unit and a discussion unit, the discussion unit is connected viaa communication line to the control unit, the control unit repeatedlytransmits and receives a running packet to and from the discussion unit,the running packet includes a counter flag, the control unit includes aCU communication portion, a CU storage portion, and a CU controlportion, the discussion unit includes a DU control portion and a DUcommunication portion, the CU control portion resets a count value ofthe counter flag included in the running packet transmitted to thediscussion unit, the CU communication portion transmits the runningpacket to the discussion unit, the DU control portion increments thecount value of the counter flag, the DU communication portion transmitsthe running packet, which includes the counter flag with the incrementedcount value, to the control unit, the CU storage portion stores thecount value of the counter flag included in the running packet receivedby the control unit from the discussion unit, and each time the controlunit receives the running packet from the discussion unit, the CUcontrol portion compares the count value stored in the CU storageportion and the count value of the counter flag included in the runningpacket received by the control unit from the discussion unit.

Advantageous Effects of Invention

According to the present invention, a conference system, capable ofreliably managing a connection state of a discussion unit and a controlunit and continuously acquiring information from the discussion unitwhen a connection abnormality occurs, can be provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a network configuration diagram of an embodiment of aconference system according to the present invention.

FIG. 2 is a functional block diagram of a hardware configuration of acontrol unit included in the conference system of FIG. 1.

FIG. 3 is a data structure diagram of a packet transmitted and receivedby the control unit of FIG. 2.

FIG. 4 is a schematic diagram of an example of information stored in astorage portion of the control unit of FIG. 2.

FIG. 5 is a schematic diagram of other information stored in the storageportion of the control unit of FIG. 2.

FIG. 6 is a perspective view of a discussion unit included in theconference system of FIG. 1.

FIG. 7 is a functional block diagram of a hardware configuration of thediscussion unit of FIG. 6.

FIG. 8 is a rear view of the discussion unit of FIG. 6.

FIG. 9 is a perspective view of the discussion unit of FIG. 6 with amicrophone mounted thereon.

FIG. 10 is a functional block diagram of a hardware configuration of anoperating station included in the conference system of FIG. 1.

FIG. 11 is a flowchart of information processing by a conference systemaccording to the present invention that includes a single control unit.

FIG. 12 is a flowchart of information processing by the control unit ininitialization processing of the information processing of FIG. 11.

FIG. 13 is a sequence diagram of information processing by theconference system in the initialization processing of FIG. 12.

FIG. 14 is another sequence diagram of information processing by theconference system in the initialization processing of FIG. 12.

FIG. 15 is yet another sequence diagram of information processing by theconference system in the initialization processing of FIG. 12.

FIG. 16 is a schematic diagram of an example of information stored in astorage portion of the control unit after the initialization processingof FIG. 12.

FIG. 17 is a flowchart of information processing by the control unit inDU information acquisition processing of the information processing ofFIG. 11.

FIG. 18 is a sequence diagram of information processing by theconference system in the DU information acquisition processing of FIG.17.

FIG. 19 is a schematic diagram of an example of information stored inthe storage portion of the control unit after the DU informationacquisition processing of FIG. 17.

FIG. 20 is a flowchart of information processing by the control unit inDU setting processing of the information processing of FIG. 11.

FIG. 21 is a sequence diagram of information processing by theconference system in the DU setting processing of FIG. 20.

FIG. 22 is a flowchart of information processing by the control unit inrunning processing of the information processing of FIG. 11.

FIG. 23 is a sequence diagram of information processing by theconference system in the running processing of FIG. 22.

FIG. 24 is a sequence diagram of information processing by theconference system when there is a change in a connection state of thediscussion unit in the running processing of FIG. 22.

FIG. 25 is a flowchart of information processing by the control unit inchange processing of the running processing of FIG. 22.

FIG. 26 is a sequence diagram of information processing by theconference system as an example of initialization processing in thechange processing of FIG. 25.

FIG. 27 is a schematic diagram of an example of information stored inthe storage portion of the control unit after the change processing ofFIG. 25.

FIG. 28 is a flowchart of information processing by the control unit inrequest processing of the running processing of FIG. 22.

FIG. 29 is a sequence diagram of information processing by theconference system in the request processing of FIG. 28.

FIG. 30 is a flowchart of other information processing by the controlunit in request processing of the running processing of FIG. 22.

FIG. 31 is a flowchart of information processing by a conference systemaccording to the present invention that includes a plurality of controlunits.

FIG. 32 is a sequence diagram of information processing by theconference system in CU connection state check processing of theinformation processing of FIG. 31.

FIG. 33 is a sequence diagram of information processing by theconference system in secondary CU information acquisition processing ofthe information processing of FIG. 31.

FIG. 34 is a sequence diagram of information processing by theconference system in secondary DU initialization processing of theinformation processing of FIG. 31.

FIG. 35 is a sequence diagram of information processing by theconference system in secondary DU information acquisition processing ofthe information processing of FIG. 31.

FIG. 36 is a schematic diagram of an example of information stored inthe storage portion of a control unit after the secondary DU informationacquisition processing of FIG. 35.

FIG. 37 is a sequence diagram of information processing by theconference system in secondary CU DB information acquisition processingof the information processing of FIG. 31.

FIG. 38 is a sequence diagram of information processing by theconference system in secondary DU setting processing of the informationprocessing of FIG. 31.

FIG. 39 is a flowchart of information processing by the control units inpriority resetting processing of the control units included in theconference system of FIG. 31.

FIG. 40 is a schematic diagram of an example of conference modesincluded in the conference system of FIG. 1.

FIG. 41 is a flowchart of information processing in selection of theconference mode of the conference system of FIG. 1.

FIG. 42 is a flowchart of information processing by a control unit in afree conversation mode among the conference modes of FIG. 41.

FIG. 43 is a flowchart of information processing by the control unit ina request talk mode among the conference modes of FIG. 41.

FIG. 44 is a flowchart of information processing by the control unit ina full remote mode among the conference modes of FIG. 41.

FIG. 45 is a schematic diagram of a selection screen for input screensthat is displayed on a display portion of the operating station includedin the conference system of FIG. 1.

FIG. 46 is a schematic diagram of an initial screen, which is an exampleof an input screen of FIG. 45.

FIG. 47 is a schematic diagram of a preparation screen, which is anotherexample of an input screen of FIG. 45.

FIG. 48 is a schematic diagram of the preparation screen after input ofinformation in the preparation screen of FIG. 47.

FIG. 49 is a schematic diagram of a progress screen, which is yetanother example of an input screen of FIG. 45.

DESCRIPTION OF EMBODIMENTS

Conference System (1)

Embodiments of a conference system according to the present inventionwill now be described with reference to the attached drawings.

Configuration of the Conference System

FIG. 1 is a network configuration diagram of an embodiment of aconference system according to the present invention.

The conference system S is used, for example, in an assembly or otherconference, etc., attended by a large number of participants. Theconference system S facilitates smooth progress of the conference andperforms preparation of conference minutes, etc. The conference system Sincludes control units (referred to hereinafter as “CUs”) 1A to 1C,discussion units (referred to hereinafter as “DUs”) 2A1 to 2A4, 2B1 to2B4, and 2C1 to 2C4, microphones 3A1 to 3A4, 3B1 to 3B4, and 3C1 to 3C4,and an operating station 4.

The CUs 1A to 1C are all the same in configuration. The DUs 2A1 to 2A4,2B1 to 2B4, and 2C1 to 2C4 are all the same in configuration. Themicrophones 3A1 to 3A4, 3B1 to 3B4, and 3C1 to 3C4 are all the same inconfiguration.

In the description that follows, when there is no need to distinguishamong each of the CUs 1A to 1C, each will be referred to generically as“CU 1.” When there is no need to distinguish among each of the DUs 2A1to 2A4, 2B1 to 2B4, and 2C1 to 2C4, each will be referred to genericallyas “DU 2.” When there is no need to distinguish among each of themicrophones 3A1 to 3A4, 3B1 to 3B4, and 3C1 to 3C4, each will bereferred to generically as “microphone 3.”

The number of CUs 1 and the number of DUs 2 that configure theconference system S are not restricted to those of the presentembodiment. That is, for example, the number of DUs 2 connected to eachCUs 1 may differ.

Mode of Connection of the DUs to the CUs

Next, the mode of connection of a plurality of DUs 2 to a CU 1 will bedescribed.

A plurality of DUs 2 are connected to a CU 1 by a connection mode thatis either a ring connection mode (referred to hereinafter as “ringconnection”) or a daisy chain connection mode (referred to hereinafteras “daisy connection”).

A ring connection is a connection mode where a plurality of DUs 2 areconnected to a CU 1 in a ring. For example, the DUs 2A1 to 2A4 areconnected by a ring connection to the CU 1A. When DUs 2 are connected toa CU 1 by a ring connection, two terminals of a unit connection portionof the CU 1, to be described below, are used.

A daisy connection is a connection mode where a plurality of DUs 2 areconnected sequentially in a chain to a CU 1. For example, the DUs 2C1 to2C4 are connected by a daisy connection to the CU 1C. When DUs 2 areconnected to a CU 1 by a daisy connection, one terminal of the unitconnection portion of the CU 1, to be described below, is used.

The form of connection of the CUs 1 and the DUs 2 is not restricted tothat of the present embodiment. That is, for example, a plurality of DUs2 may be connected to a single CU 1 with the two connection modes ofring connection and daisy connection being mixed. That is, some DUs 2may be ring-connected to the CU 1 and other DUs 2 may be daisy-connectedto the same CU 1.

Connection of the CUs to the CUs

Next, the connection of the CUs 1 to each other will be described.

The three CUs 1 are connected by a daisy connection. For example, the CU1B and the CU 1C are connected by a daisy connection to the CU 1A. Inthis case, the CU 1A is set to be a primary unit and each of CU 1B andCU 1C is set to be secondary units. The primary and secondary units willbe described below.

Power is supplied to each CU 1 individually via an AC adapter, etc. Thatis, the supplying of power among the CUs 1 is not performed. Therefore,in the conference system S, the respective CUs 1 are installable,without restriction of power supply, at locations that are mutuallyseparated physically.

Configuration of the CU

FIG. 2 is a functional block diagram of a hardware configuration of a CU1.

The CU 1 controls operations of the DUs 2 and controls operations of theentire conference system S. The CU 1 includes a communication portion11, a connection portion 12, a storage portion 13, a display portion 14,an operating portion 15, and a control portion 16.

The communication portion 11 realizes communication with the other CUs1, the DUs 2, the operating station 4, an external equipment 5, etc.,via the connection portion 12. The communication portion 11 performscommunication, for example, in compliance with IEEE (Institute ofElectrical and Electronics Engineers) 802.3.

Communication between the CU 1 and a DU 2 or between the CU 1 that isthe primary unit and a CU 1 that is a secondary unit, etc., is executedby transmission and reception of a packet. The packet includes a headerportion and a data portion.

FIG. 3 is a data structure diagram of the packet.

The header portion includes an address used for communication and acounter flag to be described below. The data portion includes regionsstoring a control command, audio information, unit information, etc., tobe described below, and a request flag to be described below. Thecontrol command is a command by which the CU 1 instructs a DU 2 or acommand by which the CU 1 that is the primary unit instructs a CU 1 thatis a secondary unit, etc. The data portion does not include the controlcommand when there is no instruction from the CU 1 to a DU 2 or whenthere is no instruction from the CU 1 that is the primary unit to a CU 1that is a secondary unit. The audio information is information generatedby the DUs 2 based on audio signals from the microphones 3. The audioinformation is stored in the data portion of the packet transmitted fromthe DUs 2 to the CU 1.

The data portion includes a plurality of regions (referred tohereinafter as “audio regions”) in which the audio information isstored. The audio regions are frames that define the number of DUs 2,among the plurality of DUs 2 included in the conference system S,enabling speech at the same time. The number of audio regions includedin the data portion is the same as a set maximum number of speakers tobe described below. The CU 1 assigns a unique number (for example, 1, 2,3, . . . ) to each audio region. Details of the audio regions will bedescribed below.

FIG. 2 is referred to again.

The connection portion 12 is an interface connecting to the other CUs 1,the DUs 2, the operating station 4, the external equipment 5, etc. Theconnection portion 12 includes an external equipment connection portion12 a and a unit connection portion 12 b.

The external equipment connection portion 12 a is an interfaceconnecting to, for example, the operating station 4, the externalequipment 5, a communication equipment, etc. The external equipmentconnection portion 12 a is, for example, a USB (Universal Serial Bus)terminal, a network terminal, or an analog input/output terminal, etc.The external equipment 5 is, for example, a USB memory, a microphone, aloudspeaker, or a translation system, etc. The communication equipmentis a hub, a router, or a wireless LAN (Local Area Network) access point,etc.

The unit connection portion 12 b is an interface connecting to the otherCUs 1 and the DUs 2. The unit connection portion 12 b includes, forexample, a first terminal, a second terminal, a third terminal, and afourth terminal. The first terminal and the second terminal are, forexample, connection terminals connectable only to DUs 2. The thirdterminal and the fourth terminal are, for example, connection terminalsconnectable to either other CUs 1 or DUs 2.

The configuration of the terminals of the unit connection portion 12 bis not restricted to that of the present embodiment. That is, forexample, the number of terminals may be “6.”

The storage portion 13 stores information required by the CU 1 and theDUs 2 to realize information processing to be described below. Thestorage portion 13 is configured of a RAM (Random Access Memory),temporarily storing various information and programs, etc., a ROM (ReadOnly Memory), or a hard disk, etc.

The information stored in the storage portion 13 includes, for example,control information, for controlling operations of the CU 1 and the DUs2 and other operations of the conference system S, etc. The controlinformation includes, for example, unit setting information, unitconnection information, information related to system setting of theconference system S to be described below, a speech request list, etc.

The unit setting information is information related, for example, tosettings of DUs 2 connected to the CU 1 in the past. The unit settinginformation includes, for example, parameter information and modeinformation. The unit setting information is stored in a unit settinginformation database (referred to hereinafter as “unit settinginformation DB”).

FIG. 4 is a schematic diagram of an example of information stored in theunit setting information DB.

The unit setting information DB is a database in which, for example, anabsolute ID, configured from a serial number of a DU 2, and the unitsetting information of the DU 2 are stored in association. The unitsetting information of the DU 2 is stored in the unit settinginformation DB via the CU 1, for example, by a system administrator.During this time, the unit setting information of the DU 2 is stored inthe unit setting information DB upon being associated with the absoluteID of the DU 2.

FIG. 4 shows, for example, that the absolute ID “A” and the unit settinginformation “X1” are stored in association in the unit settinginformation DB.

The parameter information includes, for example, setting information(for example, an equalizer setting, a volume setting, etc.) of themicrophone 3 mounted on the DU 2, information related to a lightemitting state of a light emitting portion 28 to be described below, andpriority setting information to be described below.

The mode information is information related to an operation state ofeach DU 2. The information related to the operation state includes, forexample, a conference mode to be described below, a mic on trigger to bedescribed below, etc.

The unit connection information is information related to connection ofthe DUs 2 that are connected to the CU 1. The unit connectioninformation is information related to the connection mode and the numberof connected units of DUs 2 connected to the CU 1. The unit connectioninformation is stored in a unit connection information database(referred to hereinafter as “unit connection information DB”).

FIG. 5 is a schematic diagram of information stored in the unitconnection information DB.

The unit connection information DB is a database in which informationrelated to the connection of the DUs 2 that are connected to the CU 1 isstored. The unit connection information DB is prepared each time the CU1 is started. “Terminal No.” is the number of a terminal of the unitconnection portion 12 b. “Connection mode” indicates the modes ofconnection of the DUs 2 to the four terminals of the unit connectionportion 12 b. “Number of units” is the number of DUs 2 connected to eachterminal. “Relative ID” is an ID (for example, a consecutive numberstarting from 1) assigned in a relative manner to each DU 2. “AbsoluteID” is an ID that is assigned in an absolute manner to each DU 2.

FIG. 5 shows, for example, that the terminal No. “1,” the connectionmode “Ring,” the number of units “4,” the relative IDs “1” to “4,” andthe absolute IDs “A” to “D” are stored in association in the unitconnection information DB. The same figure shows that the relative IDs“1,” “2,” “3,” and “4,” and the absolute IDs “A,” “B,” “C,” and “D” arestored in association in the unit connection information DB.

FIG. 2 is referred to again.

The display portion 14 displays for example, a volume, an audiorecording status, a preset pattern, alarm information, etc., of theentire conference system S. The display portion 14 is a displayrepresented, for example, by an LCD (Liquid Crystal Display) or anorganic EL (Organic Electroluminescence) display, etc.

The operating portion 15 performs change of display contents displayedon the display portion 14, etc. The operating portion 15 is configured,for example, of a dial, a button, etc.

The control portion 16 performs control of operations of the CU 1,control of operations of the DUs 2 connected to the CU 1, calculationand processing of information, etc. The control portion 16 controlsoperations of the communication portion 11, the storage portion 13, thedisplay portion 14, and the operating portion 15. The control portion 16is configured, for example, of a microprocessor, such as a CPU (CentralProcessing Unit), etc., and its peripheral circuit.

For example, if when the CU 1B and the CU 1C are connected to the CU 1Aas shown in FIG. 1, the CU 1A is set as the primary unit, the controlportion 16 of the CU 1A also performs control of operations of the CU 1Band the CU 1C and operations of the DUs 2B1 to 2B4 and the DUs 2C1 to2C4. That is, the control portion 16 of the CU 1 that is the primaryunit also performs control of operations of the CUs 1 that are secondaryunits and control of operations of the DUs 2 connected to the CUs 1 thatare secondary units.

Configuration of the DU

FIG. 6 is a perspective view of a DU 2.

FIG. 7 is a functional block diagram of a hardware configuration of theDU 2.

FIG. 8 is a rear view of the DU 2.

The DU 2 generates audio information based on audio signals input fromthe microphone 3, transmits the audio information to the CU 1, receivessynthesized audio information (audio information transmitted to the CU 1by the other DUs 2), to be described below, from the CU 1, and outputssound waves. The DU 2 is, for example, assigned to each participant of aconference. The DU 2 is connected via a communication line to the CU 1and the other DUs 2. The DU 2 includes a housing 20, a communicationportion 21, a connection portion 22, a storage portion 23, a displayportion 24, an operating portion 25, a control portion 26, a loudspeaker27, and a light emitting portion 28.

The housing 20 houses the communication portion 21, the storage portion23, the control portion 26, and the loudspeaker 27. The housing 20includes at least a first surface 20 a and a second surface 20 b.

The first surface 20 a is disposed at a front side of the housing 20.The first surface 20 a is disposed at a position visible to a user ofthe DU 2 (referred to hereinafter as “user”) during use of the DU 2. Thefirst surface 20 a includes a plurality of emission holes 20 ah.

The emission holes 20 ah emit sound waves from the loudspeaker 27 to theexterior of the DU 2. The emission holes 20 ah are disposed at the firstsurface 20 a.

The second surface 20 b is disposed at a rear side of the housing 20.The second surface 20 b is disposed at a position (rear of the DU 2,etc.) visible to a user of another DU 2, etc. (referred to hereinafteras “third party”) during use of the DU 2.

The communication portion 21 realizes communication with the CU 1. Thecommunication portion 21 performs communication in compliance, forexample, with IEEE 802.3. Information transmitted and received by thecommunication portion 21 includes, for example, the audio informationgenerated based on the audio signals from the microphone 3, the unitsetting information, the audio information from the other DUs 2, etc.

The connection portion 22 is connected to the CU 1, the other DUs 2, themicrophone 3, etc. The connection portion 22 includes a socket portion22 a and a unit connection portion 22 b. The socket portion 22 a is asocket to which the microphone 3 is connected. The socket portion 22 ais, for example, a socket for three-pin plug defined in JEITA RC-5236“Circular connectors, latch lock type for audio equipment.” The socketportion 22 a is disposed at the first surface 20 a.

The unit connection portion 22 b is an interface connected to the CU 1and the other DUs 2. The unit connection portion 22 b includes twoterminals. With the exception of the DU 2 at a terminal end of a daisyconnection, each of the two terminals is connected either to the CU 1 oranother DU 2. Transmission and reception of information between twoterminals are controlled by the communication portion 21.

The storage portion 23 stores information required by the DU 2 torealize the information processing to be described below. The storageportion 23 is configured, for example, of a RAM or a ROM, etc. Thestorage portion 23 stores the unit setting information, etc., receivedby the communication portion 21. The unit setting information stored inthe storage portion 23 includes, for example, parameter information ofthe DU 2, information determining the light emitting state of the lightemitting portion 28 to be described below, etc.

The display portion 24 displays, for example, the volume of a headphone(not shown), etc., connected to the DU 2, a channel for secondary audio(for example, the voice of an interpreter, etc.). The display portion 24is a display represented, for example, by an LCD or an organic ELdisplay, etc. The display portion 24 is disposed on the first surface 20a of the housing 20.

The operating portion 25 outputs a detection signal, which is inaccordance with operating by the user, to the control portion 26. Theoperating portion 25 includes an operating button 25 a, a volumeadjustment button 25 b, and a channel change button 25 c. The operatingportion 25 is disposed on the first surface 20 a of the housing 20.

The operating button 25 a is depressed by the user, for example, whenthe user makes a speech request to be described below. The volumeadjustment button 25 b is operated by the user when the user adjusts thevolume of the headphone, etc., connected to the DU 2. The channel changebutton 25 c is operated by the user when the channel for secondary audio(interpretation, etc.) is to be changed.

The control portion 26 performs processing of the audio signals from themicrophone 3, control of operations of the DU 2, generation of the audioinformation, etc. The control portion 26 performs control of operationsof the communication portion 21, the storage portion 23, the displayportion 24, the operating portion 25, the loudspeaker 27, and the lightemitting portion 28. The control portion 26 is configured, for example,of a microprocessor, such as a CPU, etc., and its peripheral circuit.

The loudspeaker 27 converts the audio signals from the communicationportion 21 to sound waves and outputs the sound waves. The sound wavesfrom the loudspeaker 27 are emitted to the exterior of the DU 2 from theemission holes 20 ah of the first surface 20 a.

The light emitting portion 28 emits light based on a signal from thecontrol portion 26 to notify status information using light. The lightemitting portion 28 is, for example, a multi-color LED (Light-EmittingDiode). That is, the light emitting portion 28 is capable of emittinglight at a plurality of colors. The light emitting portion 28 includes afirst light emitting portion 28 a and a second light emitting portion 28b.

The status information includes, for example, information indicating anoperation state of the microphone 3, such as on/off of the microphone 3,etc., information indicating the operation state of the DU 2, such asinformation indicating whether or not the speech request, to bedescribed below, is being executed, etc., group information to bedescribed below, etc. The speech request is a request for turning on themicrophone 3 to enable speech by the user. The speech request is madefrom the DU 2 to the CU 1.

The first light emitting portion 28 a notifies the status information tothe user. The first light emitting portion 28 a is disposed at theoperating button 25 a.

The second light emitting portion 28 b notifies the status informationto a third party. The second light emitting portion 28 b is disposed onthe second surface 20 b of the housing 20. That is, the second lightemitting portion 28 b is visible to the third party.

The light emitting state of the light emitting portion 28 is controlled,based on the unit setting information, by the control portion 26. Thelight emitting state of the light emitting portion 28 includes a lightemitting pattern and a light emitting color. The light emitting state ofthe light emitting portion 28 is stored as unit setting information inthe storage portion 23. The light emitting pattern includes an unlitpattern, a lit pattern, a blinking pattern, and a dimmer (dimmed) litpattern.

The light emitting color is selected, for example, from among ten colorsset in advance by a system administrator, etc. By differences in thelight emitting color, the light emitting portion 28 can display, forexample, the group information. The group information is informationindicating for example, contents classified in groups based onaffiliation (country, political party, etc.) of a participant of aconference, etc., a participant's language, a priority level to bedescribed below, etc. Therefore, for example, the system administratorcan readily execute a change of setting, etc., based on the lightemitting color of the second light emitting portion 28 b.

Power is supplied to the DU 2 via a communication line cable from the CU1 connected to the respective DUs 2.

Configuration of the Microphone

FIG. 9 is a perspective view of the DU 2 with the microphone 3 mountedthereon.

The microphone 3 collects the voice (sound waves) of the user. That is,the microphone 3 converts sound waves to electric signals. Themicrophone 3 is, for example, a gooseneck type condenser microphone. Thedirectivity of the microphone 3 is, for example, unidirectional. Themicrophone 3 is mounted on the socket portion 22 a of the DU 2. Power issupplied to the microphone 3 from the DU 2, for example, by a phantompower supply. The microphone collects the voice and outputs audiosignals in an “On” state and does not collect the voice in the “Off”state.

The microphone 3 may include, for example, a single color LED ring. Inthis case, power is supplied to the LED ring from the DU 2 via thesocket portion 22 a of the DU 2.

Configuration of the Operating Device

FIG. 10 is a functional block diagram of a hardware configuration of theoperating station 4.

The operating station 4 is a station at which running of the conferencesystem S, setting of the CUs 1, setting of the DUs 2, remote control ofthe CUs 1 and the DUs 2, etc., are performed. The setting of the CUs 1and the setting of the DUs 2 are performed, for example, by a systemadministrator or a chairman of the conference, etc., operating theoperating station 4.

The operating station 4 is, for example, a general-purpose informationprocessing device, such as a PC (Personal Computer), a tablet device, ora smartphone, etc. The operating station 4 is connected to the CUs 1 viathe communication line and connected to the DUs 2 via the CUs 1 and thecommunication line. The operating station 4 includes a communicationportion 41, a storage portion 43, a display portion 44, an operatingportion 45, and a control portion 46.

The communication portion 41 realizes communication with the CUs 1. Thecommunication portion 41 is an interface connected to the CUs 1 via acommunication network, such as a LAN or WAN (Wide Area Network), etc.

The storage portion 43 stores information required by the operatingstation 4 to realize the information processing to be described below.The storage portion 43 is configured, for example, of a RAM, a ROM, or ahard disk, etc. The information stored in the storage portion 43includes various databases read from the CUs 1, the speech request listto be described below, etc.

The display portion 44 displays an operating screen of the conferencesystem S, various databases, the speech request list, etc., inaccordance with an instruction (control) from the control portion 46.The display portion 44 is, for example, a display, such as an LCD.

The operating portion 45 outputs a detection signal, which is inaccordance with the system administrator, etc., operating the operatingstation 4, to the control portion 46. The operating portion 45 is, forexample, a keyboard, a mouse, or a software keyboard, etc.

The control portion 46 performs control of operations of the operatingstation 4. The control portion 46 is configured, for example, of amicroprocessor, such as a CPU, etc., and its peripheral circuit.

The operating station 4 may be a station dedicated to a conferencesystem instead of a general-purpose information processing station.

Also, it suffices for the conference system S to include at least a CU1, a DU 2, and a microphone 3. That is, for example, the conferencesystem S does not have to include the operating station 4.

Priority

Priority is information, which, for example, the system administratorsets for the respective DUs 2 via the CUs 1 and is, so to speak, apriority right related to restriction of functions of each DU 2. A DU 2,for which the priority is set, always has an audio slot and anabove-described audio region assigned thereto and is controlled toenable speech. With a DU 2 that is controlled to enable speech, themicrophone 3 can be turned on and audio information can be transmittedto the CU 1. The priority setting of each speech-enabled DU 2 is storedin the unit setting information DB in the storage portion 13.

The audio slots are, so to speak, frames that define the number of DUs2, among the plurality of DUs 2 included in the conference system S,enabling speech at the same time. The conference system S includes audioslots of the same number as the set maximum number of speakers to bedescribed below, that is, the same number as the number of audio regionsdescribed above. The conference system S assigns a unique number (forexample, 1, 2, 3, . . . ) to each audio slot. The audio slots areincluded, for example, in the control portions 16 of the CUs 1.

Each CU 1 assigns an audio slot and an audio region to each DU 2 withwhich speech is permitted. That is, the CU 1 assigns an audio slotnumber and an audio region number to each DU 2 with which speech ispermitted. A DU 2, to which the audio slot and the audio region areassigned, enables speech. The CU 1 stores the number assigned to theaudio slot and the number assigned to the audio region in association inthe storage portion 13. The CU 1 assigns the audio slot and the audioregion to each DU 2, associates the assigned audio slot number and audioregion number, and performs a synthesis process to be described below.

The plurality of audio regions included in the data portion of a singlepacket are respectively assigned to different DUs 2. In other words, theCU 1 receives a single packet storing audio information from a pluralityof DUs 2. The CU 1 specifies a DU 2 that generated audio information bythe number of the audio region in which the audio information is stored.The CU 1 specifies the number assigned to an audio slot based on thenumber assigned to the audio region. That is, the CU 1 specifies theaudio slot and the audio region corresponding to each of thespeech-enabled DUs 2 by the audio slot number and the audio regionnumber. The CU 1 receives the audio information, stored in the audioregions of the received packet, via the audio slots corresponding to theaudio regions. The CU 1 transmits audio information received from acertain DU 2 to all of the DUs 2, including the certain DU 2, that areconnected to the CU 1.

The conference system S restricts the number of DUs 2 enabling speech atthe same time to reduce the information processing load of theconference system S and reduce network traffic. The maximum number ofDUs 2 enabling speech at the same time (referred to hereinafter as “setmaximum number of speakers”) is determined, for example, based onsettings of the CU 1 that is the primary unit. The set maximum number ofspeakers does not depend on the number of CUs 1 connected and isdetermined to be a predetermined number of units in the conferencesystem S. As mentioned above, the speech-enabled DUs 2 are the DUs 2 toeach of which the audio slot and the audio region are assigned.

The number of DUs 2 for which the priority is set (DUs 2 with whichspeech is always enabled) is set to be less than the set maximum numberof speakers. This is done for the conference system S to secure avacancy in audio slot and audio region to enable a speech request from aDU 2 for which the priority is not set to be received as well.

The priority right of a DU 2 for which the priority is set is classifiedaccording to a priority ranking of the four levels of a first right, asecond right, a third right, and a fourth right. These rights aredetermined, for example, by a combination of whether or not en blocmuting of the other DUs 2 is enabled and whether or not the DU 2 issubject to en bloc muting by another DU 2.

The first right is a priority right of being enabled to perform en blocmuting and not being subject to en bloc muting. The first right is thehighest right and is, for example, set for a DU 2 assigned to thechairman of the conference, etc. The second right is a priority right ofbeing enabled to perform en bloc muting but being subject to en blocmuting. The second right is, for example, set for a DU 2 assigned to avice-chairman of the conference, etc. The third right is a priorityright of not being enabled to perform en bloc muting and not beingsubject to en bloc muting. The fourth right is a priority right of notbeing enabled to perform en bloc muting and being subject to en blocmuting.

The conference system according to the present invention thus enablesthe priority details to be suitably set in accordance with the rights ofthe users of the DUs 2.

Operations of the Conference System

Next, operations of the conference system S will be described. Theoperations of the conference system S, that is, the informationprocessing executed by the conference system S differ in part between acase where there is one CU 1 and a case where there are a plurality ofCUs 1.

Operations of the Conference System Including a Single CU

First, the operations of the conference system S that includes a singleCU will be described.

FIG. 11 is a flowchart of information processing by the conferencesystem S that includes the single CU.

After starting of the conference system S, the conference system Sexecutes initialization processing (S1), DU information acquisitionprocessing (S2), DU setting processing (S3), and running processing(S4).

In the conference system S, the CU 1 transmits a packet from allterminals of the unit connection portion 12 b. Therefore, in the case ofa ring connection, a packet is transmitted to the DUs 2 bidirectionallyfrom each of the two terminals connected to the DUs 2. In thedescription that follows, the forward direction is the direction inwhich a packet flows from a terminal of small number among the terminalsof the ring-connected CU 1 toward a terminal of large number. Thebackward direction is the direction opposite the forward direction.

The information of the various packets received by the respectiveterminals is synthesized by the control portion 16 of the CU 1. In thisprocess, in the case of the ring connection, the information from eitherone of the terminals is muted (ignored) and not used in the synthesis bythe control portion 16. Redundancy due to synthesis of information fromboth directions is thus excluded.

Each DU 2 receives a packet at one terminal (referred to as “a”) amongthe two terminals and transmits a packet from the other terminal(referred to as “b”). The terminal (b), from which a packet istransmitted in the forward direction, receives a packet in the backwarddirection, and terminal (a), which receives a packet in the forwarddirection, transmits a packet in the backward direction.

Each processing in FIG. 11 will now be described with the CU 1A of FIG.1 and the DUs 2A1 to 2A4, connected to the CU 1A, as an example. The DU2A1 is connected to the first terminal of the CU 1A, and the DU 2A4 isconnected to the second terminal of the CU 1A.

Initialization Processing

First, the conference system S performs the initialization processing(S1). The initialization processing (S1) is processing by which the unitsettings (information) of the DUs 2, connected to the CU 1, areinitialized and the conference system S recognizes (specifies) theconnection mode and the number of connected units of DUs 2 connected tothe CU 1.

FIG. 12 is a flowchart of information processing by the CU 1A in theinitialization processing (S1).

FIG. 13 is a sequence diagram of information processing by theconference system S in the initialization processing (S1).

The control portion 16 of the CU 1A transmits an initialization command,to perform initialization of the DUs 2A1 to 2A4, to the communicationportion 11. The communication portion 11 transmits an initializationpacket carrying (including) the initialization command from the firstterminal to the DU 2A1 (S11 a). As mentioned above, each packet includesthe counter flag in the header portion. The counter flag is informationsuch that, each time the packet is transmitted to a DU 2, a count valueis incremented (has “1” added thereto) by the DU 2 receiving the packet.The control portion 16 resets the count value of the counter flagincluded in the packet transmitted to the DU 2 to initialize the countvalue. That is, the count value of the counter flag of theinitialization packet transmitted from the CU 1A to the DU 2A1 is “0.”

The DU 2A1 that received the initialization packet initializes the unitsettings in accordance with the initialization command, that is, renewsthe unit setting information in the storage portion 23 to initialvalues. The control portion 26 of the DU 2A1 that received theinitialization packet increments the count value of the counter flag(S12 a). The communication portion 21 of the DU 2A1 transmits theinitialization packet, with the count value of the counter flag being“1,” to the DU 2A2.

The DU 2A2 that received the initialization packet initializes the unitsettings in accordance with the initialization command, that is, renewsthe unit setting information in the storage portion 23 to initialvalues. The control portion 26 of the DU 2A2 that received theinitialization packet increments the count value of the counter flag(S13 a). The communication portion 21 of the DU 2A2 transmits theinitialization packet, with the count value of the counter flag being“2,” to the DU 2A3.

The DU 2A3 that received the initialization packet initializes the unitsettings in accordance with the initialization command, that is, renewsthe unit setting information in the storage portion 23 to initialvalues. The control portion 26 of the DU 2A3 that received theinitialization packet increments the count value of the counter flag(S14 a). The communication portion 21 of the DU 2A3 transmits theinitialization packet, with the count value of the counter flag being“3,” to the DU 2A4.

The DU 2A4 that received the initialization packet initializes the unitsettings in accordance with the initialization command, that is, renewsthe unit setting information in the storage portion 23 to initialvalues. The control portion 26 of the DU 2A4 that received theinitialization packet increments the count value of the counter flag(S15 a). The communication portion 21 of the DU 2A4 transmits theinitialization packet, with the count value of the counter flag being“4,” to the second terminal of the CU 1A.

The communication portion 11 receives the initialization packet from theDU 2A4 via the second terminal (S16 a).

As mentioned above, in the case of the ring connection, theinitialization packet (with the initial value of the counter flag being“0”) is also transmitted in the backward direction from the secondterminal.

FIG. 14 is another sequence diagram of information processing by theconference system S in the initialization processing (S1).

From the second terminal of the CU 1A, the initialization packet istransmitted in the backward direction in the order of the DU 2A4, the DU2A3, the DU 2A2, the DU 2A1, and the first terminal of the CU 1.

The communication portion 11 transmits the initialization packetcarrying the initialization command from the second terminal to the DU2A4 (S11 b).

The DU 2A4 initializes the unit settings and increments the count valueof the counter flag (S12 b). The DU 2A3 initializes the unit settingsand increments the count value of the counter flag (S13 b). The DU 2A2initializes the unit settings and increments the count value of thecounter flag (S14 b). The DU 2A1 initializes the unit settings andincrements the count value of the counter flag (S15 b).

The communication portion 11 receives the initialization packet from theDU 2A1 via the first terminal (S16 b).

The control portion 16 stores, in the storage portion 13, the countvalue of the counter flag and other information included in theinitialization packet received by the communication portion 11.

FIG. 15 is a sequence diagram of information processing by theconference system S after initialization packet reception in theinitialization processing (S1).

The control portion 16 recognizes, for each terminal, a connection stateof the DUs 2, that is, the connection mode and the number of connectedunits of DUs 2 (S17). The connection mode of the DUs 2 is recognized,for example, by whether or not the terminals of the unit connectionportion 12 b that transmitted and received a packet are matched(agreement/difference of the terminal No.). That is, if the terminalthat transmitted the packet matches the terminal that received thepacket, the connection mode of the DUs 2 is the daisy connection. On theother hand, if the terminal that transmitted the packet does not matchthe terminal that received the packet, the connection mode of the DUs 2is the ring connection. For example, as described above, the forwarddirection initialization packet for the DUs 2A1 to 2A4 is transmittedfrom the first terminal of the CU 1A and is received by the secondterminal. That is, the terminal No. of the terminal, by which the CU 1Atransmitted the initialization packet, does not match (differs from) theterminal No. of the terminal, by which the CU 1A received theinitialization packet. On the other hand, even in the transmission andreception of the backward direction initialization packet, the terminalNo. of the terminal (second terminal), by which the CU 1A transmittedthe initialization packet, does not match (differs from) the terminalNo. of the terminal (first terminal), by which the CU 1A received theinitialization packet. The control portion 16 thus recognizes that theconnection mode of the DUs 2A1 to 2A4 is the ring connection.

The number of connected units of DUs 2 is recognized by the count valueof the counter flag of the initialization packet transmitted andreceived by all terminals. That is, for example, the initializationpacket transmitted between the first terminal and the second terminal ofthe CU 1A returns to the CU 1A with the count value of the counter flagbeing “4.” The control portion 16 thus recognizes that the number of DUsconnected between the first terminal and the second terminal is “4.” Thecounter flag included in each packet is thus used to count the number ofDUs 2 connected to the CU 1.

When the control portion 16 recognizes the connection mode and thenumber of connected units of DUs 2, it generates IDs (referred tohereinafter as “relative IDs”) for the respective DUs 2 (S18). Therelative ID is, for example, numbered in order from the DU 2 connectedto the terminal of lower terminal No. of the unit connection portion 12b and is assigned to each DU 2. That is, for example, the relative ID ofthe DU 2A1 is “1” and the relative ID of the DU 2A4 is “4.”

The control portion 16 stores the recognized connection mode and numberof connected units of DUs 2 and the assigned relative IDs in associationin the unit connection information DB in the storage portion 13 (S19).

FIG. 16 is a schematic diagram of the information stored in the storageportion 13 of the CU 1 after the initialization processing (S1).

This figure shows that the third terminal and the fourth terminal of theCU 1 are in unconnected states of not being connected to DUs 2.

If the connection mode of the DUs 2 is the daisy connection, the DU 2 atthe terminal end determines itself to be at the terminal end becausethere is no reception from one terminal among the two terminals of theDU 2. The DU 2 at the terminal end adds a flag indicating return(referred to hereinafter as “return flag”) to the initialization packetand returns the initialization packet. That is, regardless of theconnection mode, the DUs 2 perform transmission and reception ofinformation bidirectionally. The DUs 2 do not increment the count valueof the counter flag of an initialization packet to which the return flagis added.

In this process, the control portion 16 recognizes the number ofconnected units of DUs 2 by means of the count value of the counterflag. The control portion 16 recognizes that the connection mode of theDUs 2 is the daisy connection because the terminal Nos. of the terminalsof the unit connection portion 12 b transmitting and receiving theinitialization packet are matched.

DU Information Acquisition Processing

FIG. 11 is referred to again.

Next, the conference system S executes the DU information acquisitionprocessing (S2). The DU information acquisition processing (S2) isprocessing by which the unit information of each DU 2 is acquired. Theunit information includes a serial number (absolute ID), MAC (MediaAccess Control) address, etc., of each DU 2. Description of theprocessing in the backward direction will be omitted in the followingdescription because the processing in the forward direction is the sameas the processing in the backward direction.

FIG. 17 is a flowchart of information processing by the CU 1A in the DUinformation acquisition processing (S2).

FIG. 18 is a sequence diagram of information processing by theconference system S in the DU information acquisition processing (S2).

The control portion 16 transmits an information acquisition command toacquire the unit information of the DUs 2A1 to 2A4 to the communicationportion 11. The communication portion 11 transmits an informationacquisition packet, carrying the information acquisition command, toeach of the DUs 2A1 to 2A4 (S21 a to S21 d). The address of theinformation acquisition packet is designated by a relative ID.Therefore, only the DUs 2 of the designated addresses receive theinformation acquisition packet.

Each of the DUs 2A1 to 2A4 that received the information acquisitioncommand transmits the information acquisition packet, carrying the unitinformation, to the CU 1A in accordance with the information acquisitioncommand (S22 a to S22 d).

The communication portion 11 receives the information acquisition packetfrom each of the DUs 2A1 to 2A4 (S23 a to S23 d).

The control portion 16 reads the unit information from the informationacquisition packet received by the communication portion 11. The controlportion 16 acquires the absolute IDs from the unit information (S24).The control portion 16 stores the acquired absolute ID and the relativeID in association in the unit connection information DB in the storageportion 13 (S25). By the control portion 16 acquiring the absolute ID,it becomes possible to perform address designation of the DUs 2 usingthe absolute IDs in processing subsequent to the DU informationacquisition processing (S2).

When in the DU information acquisition processing (S2), there is presenta newly connected DU 2, the control portion 16 reads the unit settinginformation DB from the storage portion 13 and makes the absolute ID andthe setting information (initial values) of the DU 2 be stored inassociation in the unit setting information DB.

FIG. 19 is a schematic diagram of the information stored in the storageportion 13 of the CU 1 after the DU information acquisition processing.

The figure shows that the relative IDs “1,” “2,” “3,” and “4” of thefour DUs 2 that are ring-connected to the terminals of terminal Nos. “1”and “2” are associated with the absolute IDs “A,” “B,” “C,” and “D.”

By the absolute IDs and the relative IDs being associated, the CU 1 ismade capable of notifying information, indicating DUs 2 of whichabsolute IDs are connected to which relative IDs, to, for example, thesystem administrator, etc., via the operating station 4, etc. Therefore,the system administrator can, for example, operate the operating station4 to make the absolute IDs and user names (proper names) of the DUs 2 bestored in association in the storage portion 13 and manage the DUs 2 bymeans of the proper names. Also, for example, by making the relative IDsand the user names of the DUs 2 be stored in association in the storageportion 13, the system administrator can make the proper names of eachseat in a conference room be displayed on the display portion 44 of theoperating station 4, etc.

DU Setting Processing

FIG. 11 is referred to again.

Next, the conference system S executes the DU setting processing (S3).The DU setting processing (S3) is processing by which setting of the DUs2 is performed based on the unit setting information DB. Description ofthe processing in the backward direction will be omitted in thefollowing description because the processing in the forward direction isthe same as the processing in the backward direction.

FIG. 20 is a flowchart of information processing by the CU 1A in the DUsetting processing (S3).

FIG. 21 is a sequence diagram of information processing by theconference system S in the DU setting processing (S3).

The control portion 16 reads the unit setting information DB from thestorage portion 13 (S31) and transmits a unit setting command, toperform setting of the DUs 2, to the communication portion 11. Thecommunication portion 11 transmits a setting packet, carrying the unitsetting command, to each of the DUs 2A1 to 2A4 (532 a to 532 d). Thesetting packet includes the absolute ID of a DU 2 as the transmissiondestination of the packet. That is, the address of the transmissiondestination of the setting packet is designated by the absolute ID.Therefore, among the DUs 2 connected to the CU 1, only the DUs 2 of thedesignated addresses receive the setting packet.

Each of the DUs 2A1 to 2A4 that received the setting packet changes theunit settings in accordance with the unit setting command (S33 a to S33d). Each of the DUs 2A1 to 2A4 renews the unit setting information inthe storage portion 23. The unit settings are information defining theoperations of each DU 2, for example, the priority setting, a setting ofthe mic on trigger to be described below, a light emitting color settingof the light emitting portion 28, etc.

The communication portion 11 receives the setting packet from each ofthe DUs 2A1 to 2A4 that changed the unit settings (S34 a to S34 d). Atthis point, the setting packet includes information indicating that eachof the DUs 2A1 to 2A4 acquired the command correctly.

When the DU setting processing (S3) is completed, running of theconference system S (for example, acquisition of audio information fromeach DU 2, etc.) is enabled.

Running Processing

FIG. 11 is referred to again.

Next, the conference system S executes the running processing (S4). Therunning processing (S4) is processing by which a running packet istransmitted periodically (for example, at every 166 μsec) from the CU 1to the DUs 2 to execute various commands carried by the running packetand monitor the connection state of the DUs 2 by means of the counterflags.

The various commands include, for example, an audio acquisition command,etc. The audio acquisition command is a command by which the CU 1acquires audio information from the DUs 2 with audio slots and audioregions assigned.

As mentioned above, there is a case where the running packet does notcarry (include) a control command. Even in this case, the running packetis transmitted and received repeatedly between the CU 1 and the DUs 2.That is, regardless of whether or not there is a control command, the CU1 uses the counter flag included in the running packet to monitor theconnection state of the DUs 2.

FIG. 22 is a flowchart of information processing by the CU 1A in therunning processing (S4).

FIG. 23 is a sequence diagram of information processing by theconference system S in the running processing (S4).

The running process (S4) will now be described with the acquisition ofaudio information from the DU 2A2, to which an audio slot and an audioregion are assigned, as an example. The assignment of audio slot andaudio region will be described below.

The control portion 16 transmits the audio acquisition command to thecommunication portion 11. The communication portion 11 transmits arunning packet, carrying the audio acquisition command, to the DU 2A2,to which an audio slot and an audio region are assigned (S41).

In accordance with the audio acquisition command, the communicationportion 21 of the DU 2A2 that received the running packet transmitsaudio information to the CU 1A by making the information be carried inthe audio region, which, among the audio regions of the running packet,is of the number assigned to the DU 2A2 itself (S42).

Here, although not shown, the count value of the counter flag is resetat the CU 1A and incremented at each of the DUs 2A1 to 2A4 as in theinitialization processing (S1).

The CU 1A receives the running packet from the DU 2A2 (S43). Thecommunication portion 11 transmits information, such as the count valueof the counter flag, audio information, etc., received by all terminalsof the unit connection portion 12 b to the control portion 16. The audioinformation is received by the audio slot of the same number as thenumber of the audio region in which the audio information was stored.Processing of the audio information will be described below. The controlportion 16 checks (specifies) the connection state (connection mode andnumber of connected units) of the DUs 2 by means of the count value ofthe counter flag and the terminal Nos. of the terminals that transmittedand received the running packet (S44). This check is executed each timethe communication portion 11 receives a running packet.

The check of the number of connected units of DUs 2 is executed bycomparing the newly acquired counter flag count value (referred tohereinafter as “new DU count value”) with the count value stored in thestorage portion 13 (referred to hereinafter as “old DU count value”).That is, when the new DU count value matches the old DU count value, thecontrol portion 16 judges that there is no change in the number ofconnected units of DUs 2. On the other hand, when the new DU count valueand the old DU count value are not matched (are mismatched), the controlportion 16 judges that there is a change in the number of connectedunits of DUs 2.

As described above, the check of the connection mode of the DUs 2 isexecuted by comparing the terminal No. of the terminal that transmitteda running packet and the terminal No. of the terminal that received therunning packet. That is, when the terminal Nos. of the terminals thattransmitted and received the running packet are matched, the controlportion 16 judges the connection mode of the DUs 2 to be the daisyconnection. On the other hand, when the terminal Nos. of the terminalsthat transmitted and received the running packet are not matched (aremismatched), the control portion 16 judges the connection mode of theDUs 2 to be the ring connection.

The control portion 16 reads the unit connection information DB from thestorage portion 13 and compares the connection mode of the DUs 2 storedin the unit connection information DB and the newly acquired connectionmode of the DUs 2. The control portion 16 judges that there is no changein the connection mode of the DUs 2 when both connection modes arematched (are the same) and judges that there is a change in theconnection mode of the DUs 2 when both connection modes are not matched(differ).

When the control portion 16 judges that there is a change in either thenumber of connected units of DUs 2 or the connection mode of the DUs 2,it judges that there is a change in the connection state of the DUs 2.That is, when the new DU count value and the old DU count value aremismatched, the control portion 16 judges that there is a change in theconnection state of the DUs 2. On the other hand, when the controlportion 16 judges that there is no change in either, it judges thatthere is no change in the connection state of the DUs 2.

When there is a change in the connection state of the DUs 2 (“Yes” inS44), the conference system S executes change processing (S5). Thechange processing (S5) will be described below.

FIG. 24 is a sequence diagram of information processing by theconference system S when there is a change in the connection state ofthe DUs 2.

The figure shows an example where the DU 2A3 undergoes a connectionabnormality due to malfunction, disconnection, etc. For convenience ofdescription, the figure shows only the processing in the forwarddirection of a running packet that is not carrying a command.

The communication portion 11 of the CU 1A transmits a running packet tothe DU 2A1 via the first terminal (S41 a). The DU 2A1 increments thecount value of the counter flag in the running packet received (S42 a)and transmits the running packet to the DU 2A2. The DU 2A2 incrementsthe count value of the counter flag in the running packet received (S42b).

If a connection abnormality occurs in the DU 2A3, the DU 2A2 recognizesthat it itself has become the DU 2 at the terminal end because there isno reception of the running packet from one of the terminals (from thebackward direction). The DU 2A2 thus adds the return flag to (makes thereturn flag be carried by) the running packet (S42 c). The DU 2A2transmits, via the DU 2A1, the running packet, with the return flagadded, to the CU 1A. In this process, the DU 2A1 performs, as mentionedabove, only the reception and transmission of the running packet anddoes not increment the count value of the counter flag because thereturn flag is added to the running packet.

On the other hand, in the processing in the backward direction, the DU2A4 transmits, in the same manner as the DU 2A2, a running packet, withthe return flag added, to the CU 1A (not shown).

The control portion 16 of the CU 1A recognizes a change in theconnection mode of the DUs 2A1 to 2A4 (a change from the ring connectionto the daisy connection) because the terminal Nos. of the terminals thattransmitted and received each running packet are the same. The controlportion 16 recognizes a change in the number of connected units of DUs 2connected to the same terminal from the comparison results of the countvalues of the counter flags of the running packets. The control portion16 collates the recognition results and the unit connection informationDB to recognize a change in the connection state of the DUs 2A1 to 2A4(S44).

Here, the control portion 16 recognizes that a connection abnormalityoccurred in the DU 2A3 from the count value of “2” of the counter flagof the running packet received by the first terminal and the count valueof “1” of the counter flag of the running packet received by the secondterminal. Thus, when a connection abnormality occurs, the CU 1Aimmediately recognizes the occurrence of the connection abnormality andspecifies the connection abnormality location.

FIG. 22 and FIG. 23 are referred to again.

If there is no change in the connection state of the DUs 2 (“No” inS44), the control portion 16 synthesizes (processes) the audioinformation received in the audio slots by all terminals and theinformation stored in association with the absolute IDs of the DUs 2 inthe storage portion 13 to generate synthesized audio information (S45).The synthesis of audio information is executed by mutually synthesizingthe audio information stored in the audio regions of the same number,among the audio regions of the respective running packets received byall terminals.

The synthesized audio information includes, for example, information onthe users (speakers), time information, group information, and otherinformation on the DUs 2 associated with the absolute IDs. Thesynthesized audio information is stored, for example, in a USB memory,etc., connected to the external equipment connection portion 12 a of theCU 1A and is transmitted to each of the DUs 2A1 to 2A4. The synthesizedaudio information transmitted to each of the DUs 2A1 to 2A4 is processedby the control portion 26 of each of the DUs 2A1 to 2A4 and thereafterconverted to sound waves by the loudspeaker 27 and output from theloudspeaker 27.

In the process of generating the synthesized audio information, thecontrol portion 16 checks whether or not the request flag is added to arunning packet (S46). The request flag will be described below.

If the request flag is added (“Yes” in S46), the conference system Sexecutes request processing (S6). If the request flag is not added (“No”in S46), the conference system S repeats the running processing (S4).

Change Processing

When there is a change in the connection state of the DUs 2, theconference system S executes the change processing (S5). The changeprocessing (S5) is processing by which the unit connection informationstored in the unit connection information DB is renewed after the changein the connection state of the DUs 2 to prevent omission of audioinformation and problems in the synthesizing processing of audioinformation.

FIG. 25 is a flowchart of information processing by the CU 1A in thechange processing (S5).

The change processing (S5) is processing in which the initializationprocessing (S1), the DU information acquisition processing (S2), and theDU setting processing (S3) are executed anew to renew the unitconnection information stored in the unit connection information DB.

FIG. 26 is a sequence diagram of information processing by theconference system S as an example of the initialization processing (S1)in the change processing (S5). The figure shows a state where the DU 2A3undergoes a connection abnormality due to malfunction, disconnection,etc. For convenience of description, the figure shows only theprocessing in the forward direction.

In the initialization processing (S1), the communication portion 11 ofthe CU 1A transmits an initialization packet to the DU 2A1 via the firstterminal and transmits an initialization packet to the DU 2A4 via thesecond terminal. The initialization packet from the first terminal isreturned from the DU 2A2. In this process, the DU 2A2 adds a return flagto the initialization packet (S131 a). On the other hand, theinitialization packet from the second terminal is returned from the DU2A4 (not shown). In this process, the DU 2A4 adds a return flag to theinitialization packet (not shown).

The communication portion 11 receives the initialization packet from theDU 2A1 via the first terminal (S16 a) and receives the initializationpacket from the DU 2A4 via the second terminal. The control portion 16stores the new DU count values in the storage portion 13. In thisprocess, the control portion 16 renews the old DU count values with thenew DU count values.

The control portion 16 recognizes the connection state of the DUs 2,that is, the connection mode and the number of connected units of DUs 2at each terminal of the CU 1 (S17). The connection mode of the DU 2A1and the DU 2A2 connected to the first terminal of the CU 1 and theconnection mode of the DU 2A4 connected to the second terminal of thesame are daisy connections because the terminals transmitting andreceiving the initialization packet are the same. On the other hand, thenumber of connected units of DUs 2 connected to the first terminal istwo and the number of connected units of DUs 2 connected to the secondterminal is one.

The control portion 16 generates the relative IDs of the respective DUs2 when it recognizes the connection modes and the numbers of connectedunits of the DUs 2 (S18).

The control portion 16 stores the connection modes, the numbers ofconnected units, and the relative IDs of the DUs 2 in association in theunit connection information DB in the storage portion 13 (S19).Consequently, the association of the connection state of the DUs 2, therelative IDs, and the absolute IDs stored in the unit connectioninformation DB in the storage portion 13 is renewed. Thus, when the newDU count values and the old DU count values are mismatched, the controlportion 16 renews the association of the relative IDs and the absoluteIDs. When both connection modes differ, the control portion 16 renewsthe connection modes of the DUs 2 stored in the storage portion 13.

The respective processing contents of the DU information acquisitionprocessing (S2) and the DU setting processing (S3) are the same as therespective processing contents of the DU information acquisitionprocessing (FIG. 17) and the DU setting processing (FIG. 20) describedabove.

FIG. 27 is a diagram of an example of information stored in a unitconnection state DB after the change processing.

This figure, in comparison to FIG. 19, shows that the DU 2A3 is gone andthe relative ID of the DU 2A4 is changed from “4” to “3.” When such achange in the relative ID occurs, the association of the absolute IDsand the relative IDs is renewed and therefore a problem in thesynthesizing processing of audio information before and after the changein the connection state of the DUs 2, etc., does not occur.

In the change processing, if there is no change in the number ofconnected units of DUs 2, only the connection mode of the DUs 2 may berenewed without renewing the relative IDs of the DUs 2.

Request Processing

FIG. 11 is referred to again.

If in the running processing (S4), the request flag is added to arunning packet, the conference system S executes the request processing(S6). The request processing (S6) is processing by which, when a speechrequest is made from a DU 2, command management up to assignment of anaudio slot to the DU 2 is performed.

The request flag is not a command itself but is on/off of a fixed lengthof bits added to a running packet by operation by a user of a DU 2 whenthe user makes a speech request. The request flag is added to therunning packet by the control portion 26 of the DU 2. The addition ofthe request flag is executed by the control portion 26 of the DU 2processing the request flag bits (for example, a bit is set to “1” whenon and the bit is set to “0” when off). The DU 2 that added the requestflag enters a state of waiting for a command from the CU 1 (requestwaiting state). The running packet with the request flag added istransmitted from the communication portion 21 of the DU 2 to the CU 1A.The operation by the user is executed by either an operation bydepressing of the operating button 25 a (referred to hereinafter as“manual trigger”) or an operation by the user's voice (referred tohereinafter as “automatic trigger”). That is, the manual trigger and theautomatic trigger are triggers for turning “on” the microphone 3.

The DU 2 in the request waiting state is in a state (referred to hereinafter as “transmission disabled state”) of not being capable oftransmitting audio information to the CU 1 by means of the communicationportion 21. On the other hand, the DU 2 in a state (referred to hereinafter as “speech enabled state”) where the speech request is permittedby the CU 1 is in a state (referred to herein after as “transmissionenabled state”) of being capable of transmitting audio information tothe CU 1 by means of the communication portion 21.

FIG. 28 is a flowchart of information processing by the CU 1A in therequest processing (S6).

FIG. 29 is a sequence diagram of information processing by theconference system S in the request processing (S6). In the figure, onlythe sequences of the CU 1A and the DU 2A1 are shown for the convenienceof description.

When the request flag is added to the running packet received by the CU1A, the control portion 16 of the CU 1A fetches the request flag into arequest flag register (storage portion 13) (S61). In this process, thecontrol portion 16 performs the fetching of the request flag but doesnot perform transmission of a command to a DU 2. By this processing, therequest flag is fetched into the register (storage portion 13) andtherefore reception leakage (omission) of the speech request in thehardware is prevented.

Next, the control portion 16 executes masking processing of the bitcorresponding to the fetched request flag (S62). By this processing, therequest flag inside the request flag register becomes protected, thatis, the request flag becomes unrewritable. Consequently, misdetection ofthe request flag is prevented.

Next, the control portion 16 checks whether or not there is a rejectionof the request, for example, from the chairman or the systemadministrator, etc. (S63). If the request is rejected (“Yes” in S63),the control portion 16 releases the mask (S71).

If the request is not rejected (“No” in S63), the control portion 16checks whether or not there is a vacancy in audio slot and audio region(S64). If there is a vacancy in audio slot and audio region (“Yes” inS64), the control portion 16 transmits an acquisition command, toacquire the content of the request, to the communication portion 11. Thecommunication portion 11 transmits a content acquisition packet,carrying the acquisition command, to the DU 2A1 (S65).

The communication portion 21 of the DU 2A1 that received the contentacquisition packet makes the content of the request (speech request) becarried by the content acquisition packet and transmits it to the CU 1A(S67). The DU 2A1 transmits the content of the request to the CU 1A andclears the request flag (turns of the bit for the request flag) (S66).

The clearing of the request flag may be performed by the CU 1 instead ofby a DU 2.

The communication portion 11 receives the content acquisition packet(S68) and transmits the content of the request to the control portion16. After acquisition of the content of the request, the control portion16 releases the mask (S69) and assigns an audio slot and an audio regionto the DU 2A1 (S70). Thereafter, the speech request from the DU 2A1 ispermitted. The control portion 26 of the DU 2A1 switches the state ofthe communication portion 21 from the transmission disabled state to thetransmission enabled state. That is, the DU 2A1 is put in the speechenabled state.

On the other hand, if there is no vacancy in audio slot and audio region(“No” in S64), the control portion 16 waits until there is a vacantaudio slot and audio region (no processing is performed on the DU 2A1).At this point, the DU 2A1 is automatically put in the request waitingstate. The state of the communication portion 21 of the DU 2A1 is thetransmission disabled state.

After the processing of either assigning an audio slot and an audioregion to the DU 2 (S70) or releasing of the mask (S71), the conferencesystem S returns to the running processing (S4).

The conference system S thus fetches a speech request from a DU 2 byperiodic processing of the request flag and makes the CU 1 transmit thecontent acquisition command to the DU 2 only when there is a vacantaudio slot and audio region. That is, the conference system S does nottransmit a command on each speech request. Therefore, with theconference system S, the information processing load does not becomeexcessive even when speech requests are made from a plurality of DUs 2at once.

Also, if there is no vacancy in audio slot and audio region, the DU 2that made the speech request is automatically put in the request waitingstate. Therefore, the conference system S is not required to accommodateall speech requests from the DUs 2 and the information processing loadis lightened.

Further, speech requests from the DUs 2 are made not by a command but byprocessing of the bits of the request flag. A region of a packetoccupied by the request flag may thus be set, for example, to a fewbytes. Consequently, the information processing load of the conferencesystem S for speech requests is lightened.

The flow of the request processing in the present invention is notrestricted to that of the present embodiment. That is, for example, thecheck for a vacancy in audio slot and audio region (S64) may be executedafter transmission and reception of the content acquisition packet.

FIG. 30 is a flowchart of other information processing by the CU 1A inthe request processing.

The request processing (S6 a) shown in the figure is the same as therequest processing shown in FIG. 28 with the exception that the checkfor a vacancy in audio slot and audio region (S64 a) is executedimmediately before the assignment of an audio slot and an audio region(S70). That is, in the request processing (S6 a) shown in the figure,the request flag fetching processing (S61), the masking processing(S62), the check processing of whether or not the request is rejected(S63), the processing in the case of rejection of the request (“Yes” inS63) (S71), and the audio slot and audio region assignment processing(S70) are the same as those in the request processing (S6) shown in FIG.28.

If the request is not rejected (“No” in S63), the control portion 16transmits the acquisition command to the communication portion 11. Thecommunication portion 11 transmits the content acquisition packet,carrying the acquisition command, to the DU 2A1 (S65 a).

The DU 2A1 that received the content acquisition packet clears therequest flag (S66) and makes the content of the request (speech request)be carried by the content acquisition packet and transmits it to the CU1A (S67).

The communication portion 11 receives the content acquisition packet(S68 a) and transmits the content of the request to the control portion16. After acquisition of the content of the request, the control portion16 releases the mask (S69 a) and performs a check for a vacancy in audioslot and audio region (S64 a). If there is a vacancy in audio slot andaudio region (“Yes” in S64 a), the control portion 16 assigns the audioslot and the audio region to the DU 2A1 (S70). At this point, the DU 2A1is put in the speech enabled state. On the other hand, if there is novacancy in audio slot and audio region (“No” in S64 a), the controlportion 16 waits until there is a vacant audio slot and audio region.

The flow of the respective processing by the conference system accordingto the present invention is not restricted to that of the presentembodiment. That is, for example, the conference system S may executethe respective processing not by series processing but by appropriateparallel processing.

Also, as described above, each of the various packets transmitted fromthe CU 1 to the DUs 2 includes the counter flag and the request flag.That is, the monitoring of the connection state of the DUs 2 byincrementing of the counter flag is always performed, regardless ofwhether or not there is a command, in the various packets transmittedfrom the CU 1 to the DUs 2. Also, the request flag can always be addedto the various packets transmitted from the CU 1 to the DUs 2.

Operation of the Light Emitting Portion of a DU 2 in the RequestProcessing

The light emitting state of the light emitting portion 28 changes inaccordance with the operation state of the DU 2 during the requestprocessing (S6). That is, for example, the light emitting pattern of theDU 2 becomes the blinking pattern when the DU 2 is in the requestwaiting state (transmission disabled state) and becomes the lit patternwhen the DU 2 is in the speech enabled state (transmission enabledstate). Also, when a request from the DU 2 is rejected, only the firstlight emitting portion 28 a of the light emitting portion 28 blinks at ashorter interval than in the blinking pattern in the request waitingstate to notify only to the user that the request is rejected. The lightemitting pattern of the light emitting portion 28 of the DU 2 withoutthe request flag added exhibits the unlit pattern or the dimmer litpattern. The light emitting portion 28 thus functions as a notificationportion that visually notifies operation circumstances of the DU 2.

Operations of the Conference System Including a Plurality of CUs

Next, the operations of the conference system that includes a pluralityof CUs 1 will be described.

FIG. 31 is a flowchart of information processing by the conferencesystem S that includes the plurality of CUs 1.

After the conference system S is started, the conference system Sexecutes an initialization processing (S1), a CU connection state checkprocessing (S101), a DU information acquisition processing (S2), asecondary CU information acquisition processing (S102), a secondary DUinitialization processing (S103), a secondary DU information acquisitionprocessing (S104), a secondary CU DB information acquisition processing(S105), a DU setting processing (D3), a secondary DU setting processing(S106), a priority resetting processing (S107), and a running processing(S4). A secondary CU is a CU 1 that is set as a secondary unit. Asecondary DU is a DU 2 that is connected to a CU 1 that is set as asecondary unit.

The flow of the respective processing by the conference system accordingto the present invention is not restricted to that of the presentembodiment. That is, for example, the conference system S may executethe respective processing not by series processing but by appropriateparallel processing.

In the following, a description will be provided with the CU 1A(referred to hereinafter as “primary CU”), the DUs 2A1 to 2A4 (referredto hereinafter as “primary DUs”) connected to the primary CU, the CU 1B(referred to hereinafter as “secondary CU”) connected to the primary CU,and the DUs 2B1 to 2B4 (referred to hereinafter as “secondary DUs”)connected to the secondary CU of FIG. 1 as an example.

The primary DUs are ring-connected to the first terminal and the secondterminal of the primary CU via a communication line. The secondary DUsare ring-connected to the first terminal and the second terminal of thesecondary CU via a communication line. The secondary CU is connected tothe third terminal of the primary CU.

The primary CU (CU 1A) is set as the primary unit, for example, by thesystem administrator, etc., changing CU unit information to be describedbelow. The secondary CU (CU 1B) is set as the secondary unit, forexample, by the system administrator, etc., changing the CU unitinformation to be described below. Control of the conference system Sthat includes the plurality of CUs is performed by the primary CU.

Initialization Processing

First, the conference system S executes the initialization processing(S1) of the primary DUs connected to the primary CU. The initializationprocessing (S1) is the same as the initialization processing (FIG. 12)described above.

CU Connection State Check Processing

Next, the conference system S executes the CU connection state checkprocessing (S101). The CU connection state check processing (S101) isprocessing by which the connection mode and the number of connectedunits of other CUs 1 connected to a CU 1 are recognized. The CUconnection state check processing (S101) is executed repeatedly duringoperation of the conference system S.

FIG. 32 is a sequence diagram of information processing by theconference system S in the CU connection state check processing.

The control portion 16 of the primary CU transmits a CU connection statecheck command, to check the connection state of the CUs, to thecommunication portion 11 of the primary CU. The communication portion 11of the primary CU transmits a CU connection state check packet, carryingthe CU connection state check command, to the secondary CU from thethird terminal (S1011). The control portion 16 of the primary CU resetsthe count value of the counter flag included in the packet transmittedto the secondary CU. The count value of the counter flag included in thepacket transmitted from the CU 1A to the CU 1B is thus “0.” The counterflag included in the packet transmitted from the CU 1A to the CU 1B isused to count the number of secondary CUs connected to the primary CU.

The control portion 16 of the secondary CU that received the CUconnection state check packet increments the count value of the counterflag (S1012). The communication portion 11 of the secondary CU transmitsthe CU connection state check packet, including the incremented counterflag, to the primary CU.

The communication portion 11 of the primary CU receives the CUconnection state check packet from the secondary CU via the thirdterminal (S1013).

The control portion 16 of the primary CU stores, in the storage portion13 of the primary CU, the count value of the counter flag and otherinformation included in the CU connection state check packet, receivedby the communication portion 11 of the primary CU.

The control portion 16 of the primary CU recognizes the connection stateof the CUs 1 (S1014) in the same manner as in the above-describedrecognition (S17) of the connection state of the DUs 2. That is, forexample, the control portion 16 of the primary CU recognizes, based onthe count value of the counter flag, that one secondary CU isdaisy-connected.

When the control portion 16 of the primary CU recognizes the connectionstate of the CUs 1, it generates relative IDs for the respective CUs 1(S1015).

The control portion 16 of the primary CU stores the connection mode, thenumber of connected units, and the relative IDs of the CUs 1 in the unitconnection information DB in the storage portion 13 of the primary CU(S1016).

The CU connection state check processing (S101) is repeatedly executedperiodically during operation of the conference system S. That is, theCU connection state check packet is repeatedly transmitted and receivedperiodically between the primary CU and each secondary CU. Each time itreceives the connection state check packet from a secondary CU, thecontrol portion 16 of the primary CU compares the newly acquired counterflag count value (referred to hereinafter as “new CU count value”) withthe count value stored in the storage portion 13 of the primary CU(referred to hereinafter as “old CU count value”). When the new CU countvalue matches the old CU count value, the control portion 16 of theprimary CU judges that there is no change in the connection state of theCUs 1. On the other hand, when the new CU count value and the old CUcount value are not matched (are mismatched), the control portion 16 ofthe primary CU judges that there is a change in the connection state ofthe CUs 1. The control portion 16 of the primary CU stores the new CUcount value in the storage portion 13 of the primary CU. That is, thecontrol portion 16 of the primary CU renews the old CU count value withthe new CU count value.

When the secondary CU connection state changes, as when a connectionabnormality occurs in a secondary CU or when a new secondary CU isconnected, the comparison of the new CU count value and the old CU countvalue will result in a mismatch. When the comparison result is amismatch, the control portion 16 of the primary CU renews theinformation stored in the unit connection information DB stored in thestorage portion 13 with the newly recognized secondary CU connectionstate. Thus, when a connection abnormality occurs in a secondary CU, theprimary CU immediately recognizes the occurrence of the connectionabnormality and specifies the connection abnormality location. Also,when a change occurs in the secondary CU connection state, the primaryCU renews the information stored in the unit connection information DBso that a problem in the synthesizing processing of audio informationbefore and after the change in the connection state, etc., does notoccur.

DU Information Acquisition Processing

Next, the conferencing system S executes the DU information acquisitionprocessing (S2) on the primary DUs. The DU information acquisitionprocessing (S2) is the same as the DU information acquisition processing(FIG. 17) described above.

Secondary CU Information Acquisition Processing

Next, the conferencing system S executes the secondary CU informationacquisition processing (S102). The secondary CU information acquisitionprocessing is processing by which CU unit information of each secondaryCU is acquired. The CU unit information includes a serial number(absolute ID), MAC address, etc., of each CU 1.

FIG. 33 is a sequence diagram of information processing by theconference system S in the secondary CU information acquisitionprocessing (S102).

The control portion 16 of the primary CU transmits an informationacquisition command, to acquire the CU unit information of a secondaryCU, to the communication portion 11 of the primary CU. The communicationportion 11 of the primary CU transmits an information acquisitionpacket, carrying the information acquisition command, to the secondaryCU (S1021).

The secondary CU that received the information acquisition command makesthe CU unit information be carried by the information acquisition packetand transmits it to the primary CU in accordance with the informationacquisition command (S1022).

The communication portion 11 of the primary CU receives the informationacquisition packet from the secondary CU (S1023). The communicationportion 11 of the primary CU transmits the CU unit information to thecontrol portion 16 of the primary CU.

The control portion 16 acquires the absolute ID of the secondary CU fromthe CU unit information (S1024). The control portion 16 reads the unitconnection information DB and stores the absolute ID and the relative IDin association in the unit connection information DB (S1025).

Secondary DU Initialization Processing

Next, the conference system S executes the secondary DU initializationprocessing (S103). The secondary DU initialization processing (S103) isprocessing by which the unit settings of the secondary DUs connected toeach secondary CU are initialized and the connection state of thesecondary DUs is recognized.

FIG. 34 is a sequence diagram of information processing by theconference system S in the secondary DU initialization processing(S103).

The control portion 16 of the primary CU transmits an initializationcommand, to perform initialization of the secondary DUs, to thecommunication portion 11 of the primary CU. The communication portion 11of the primary CU transmits an initialization packet carrying theinitialization command from the third terminal to the secondary CU(S1031 a).

The secondary CU that received the initialization packet transmits theinitialization packet bidirectionally from each of the first terminaland the second terminal to the secondary DUs (S1031 b). Each secondaryDU initializes the unit settings in accordance with the initializationcommand and increments the count value of the counter flag (S1032). Thesecondary DUs transmit each initialization packet, with the count valueof the counter flag incremented, to the secondary CU. As in theinitialization processing (FIG. 12), each initialization packet istransmitted among the secondary DUs.

The communication portion 11 of the secondary CU receives eachinitialization packet from the secondary DUs via each of the firstterminal and the second terminal (S1033 b). The control portion 16 ofthe secondary CU stores, in the storage portion 13 of the secondary CU,the count value of the counter flag and other information included inthe initialization packet received by the communication portion 11 ofthe secondary CU.

The control portion 16 of the secondary CU recognizes the connectionstate of the secondary DUs (S1035 b) and generates relative IDs for thesecondary DUs (S1036 b). These relative IDs are IDs that the secondaryCU uses to control the secondary DUs.

The control portion 16 of the secondary CU stores the connection mode,the number of units connected, and the relative IDs of the secondary DUsin association in the unit connection information DB in the storageportion 13 of the secondary CU (S1037 b).

The communication portion 11 of the secondary CU transmits each receivedinitialization packet to the primary CU (S1034 b).

The communication portion 11 of the primary CU receives eachinitialization packet from the secondary CU via the third terminal(S1033 a). The communication portion 11 of the primary CU transmits, tothe control portion 16 of the primary CU, the count value of the counterflag and other information obtained from each received initializationpacket. The control portion 16 of the primary CU stores the count valueof the counter flag and other information in the storage portion 13 ofthe primary CU.

The control portion 16 of the primary CU recognizes the connection stateof the secondary DUs (S1035 a) and generates relative IDs for thesecondary DUs (S1036 a). These relative IDs are IDs that the primary CUuses to control the secondary DUs.

The control portion 16 of the primary CU stores the connection mode, thenumber of connected units, and the relative IDs of the secondary DUs inassociation in the unit connection information DB in the storage portion13 of the primary CU (S1037 a).

Secondary DU Information Acquisition Processing

Next, the conference system S executes the secondary DU informationacquisition processing (S104). The secondary DU information acquisitionprocessing (S104) is processing by which the unit information of thesecondary DUs connected to the secondary CU is acquired.

FIG. 35 is a sequence diagram of information processing by theconference system S in the secondary DU information acquisitionprocessing (S104).

The control portion 16 of the primary CU transmits an informationacquisition command, to acquire the unit information of the secondaryDUs, to the communication portion 11 of the primary CU. Thecommunication portion 11 of the primary CU transmits an informationacquisition packet, carrying the information acquisition command, to thesecondary CU via the third terminal (S1041 a).

The secondary CU that received the information acquisition packettransmits the information acquisition packet bidirectionally from eachof the first terminal and the second terminal to the secondary DUs(S1041 b). Each secondary DU makes the unit information be carried oneach information acquisition packet and transmits it to the secondary CUin accordance with the information acquisition command (S1042). As inthe DU information acquisition processing (FIG. 17), each informationacquisition packet is transmitted among the secondary DUs.

The communication portion 11 of the secondary CU receives eachinformation acquisition packet from the secondary DUs (S1043 b).

The control portion 16 of the secondary CU acquires the absolute IDs ofthe secondary DUs from the unit information included in each informationacquisition packet received by the communication portion 11 of thesecondary CU (S1045 b). The control portion 16 stores the absolute IDsand the relative IDs in association in the unit connection informationDB in the storage portion 13 of the secondary CU (S1046 b). That is, thecontrol portion 16 of the secondary CU renews the association of therelative IDs and the absolute IDs in the secondary CU. Therefore, evenif a change occurs in the connection state of the primary CU and thesecondary CU, the secondary CU is capable of operation as a standaloneunit. Consequently, a problem of information in the synthesizingprocessing of audio information before and after the change in theconnection state of the secondary CU, etc., does not occur.

The communication portion 11 of the secondary CU transmits eachinformation acquisition packet to the primary CU (S1044 b).

The communication portion 11 of the primary CU receives each informationacquisition packet from the secondary CU via the third terminal (S1043a).

The control portion 16 of the primary CU acquires the absolute IDs fromthe unit information included in each information acquisition packetreceived by the communication portion 11 of the primary CU (S1045 a).The control portion 16 of the primary CU stores the absolute IDs and therelative IDs in association in the unit connection information DB in thestorage portion 13 of the primary CU (S1046 a).

FIG. 36 is a diagram of an example of information stored in the storageportion 13 of the primary CU after the secondary DU informationacquisition processing. The figure shows that the relative IDs “5,” “6,”“7,” and “8” of the four DUs 2 that are ring-connected to the terminalNos. “1” and “2” of the secondary CU (ID: “2”) are respectivelyassociated with the absolute IDs “E,” “F,” “G,” and “H.” The figureshows that the relative ID “1” of the single CU 1 that is daisyconnected to the terminal No. “3” is associated with the absolute ID“B.”

DB Information Acquisition Processing of the Secondary CU

Next, the conference system S executes the secondary CU DB informationacquisition processing (S105). The secondary CU DB informationacquisition processing (S105) is processing by which the primary CUacquires the unit setting information of the secondary DUs stored in theunit setting information DB stored in the secondary CU.

FIG. 37 is a sequence diagram of information processing by theconference system S in the secondary CU DB information acquisitionprocessing (S105).

The control portion 16 of the primary CU transmits a DB informationacquisition command, to acquire the unit setting information of thesecondary CU, to the communication portion 11 of the primary CU. Thecommunication portion 11 of the primary CU transmits a DB informationacquisition packet, carrying the DB information acquisition command, tothe secondary CU via the third terminal (S1051).

The control portion 16 of the secondary CU reads the unit settinginformation DB from the storage portion 13 of the secondary CU andtransmits the unit setting information of the secondary DUs, designatedby the primary CU, to the communication portion 11 of the secondary CU.The communication portion 11 of the secondary CU transmits the DBinformation acquisition packet, carrying the unit setting information ofthe secondary DUs, to the primary CU (S1052).

The communication portion 11 of the primary CU receives the DBinformation acquisition packet from the secondary CU via the thirdterminal (S1053). The communication portion 11 of the primary CUtransmits the unit setting information of the secondary DUs, obtainedfrom the received DB information acquisition packet, to the controlportion 16 of the primary CU.

The control portion 16 of the primary CU stores, in the unit settinginformation DB in the storage portion 13 of the primary CU, the unitsetting information of the secondary DUs included in the DB informationacquisition packet received by the communication portion 11 of theprimary CU (S1054). By this processing, the primary CU can specify theunit setting information of the secondary DUs stored in the secondaryCU.

DU Setting Processing

Next, the conference system S executes the DU setting processing (S3) onthe primary DUs connected to the primary CU. The DU setting processing(S3) is the same as the DU setting processing (FIG. 20) described above.

Secondary DU Setting Processing

Next, the conference system S executes the secondary DU settingprocessing (S106). The secondary DU setting processing (S106) isprocessing by which the setting of secondary DUs connected to thesecondary CU is performed.

FIG. 38 is a sequence diagram of information processing by theconference system S in secondary DU setting processing (S106).

The control portion 16 of the primary CU reads the unit settinginformation DB from the storage portion 13 of the primary CU (S1061) andtransmits a unit setting command, to perform the setting of secondaryDUs, to the communication portion 11 of the primary CU. Thecommunication portion 11 of the primary CU transmits a setting packet,carrying the unit setting command, to the secondary CU (S1062 a).

The secondary CU that received the setting packet transmits the settingpacket to the secondary DUs (S1062 b). The secondary DUs that receivedthe setting packet change the unit settings in accordance with the unitsetting command (S1063).

The communication portion 11 of the secondary CU receives the settingpacket from the secondary DUs that executed the change of unit settings(S1064 b).

The communication portion 11 of the secondary CU transmits the receivedsetting packet to the primary CU (S1065 b).

The communication portion 11 of the primary CU receives the settingpacket from the secondary CU (S1064 a).

Priority Resetting Processing

Next, the conference system S executes the priority resetting processing(S107). The priority resetting processing (S107) is processing by whichresolution of an inconsistent state, occurring between the prioritysettings of the respective CUs 1 and the priority settings of the entireconference system S when a change occurs in the connection state of theCUs 1 to each other (when the new CU count value and the old CU countvalue become mismatched), is performed automatically. An inconsistentstate is a state where the number of DUs 2 for which the priority is setis the same as the maximum number of units enabling speech or is greaterthan the maximum number of units enabling speech. That is, for example,an inconsistent state is a state where, when the maximum number of unitsenabling speech in the entire conference system S is five, the number ofDUs 2 for which the priority is set in the entire conference system S isseven. This inconsistent state may occur, for example, when a CU 1, withthe priority being set for three DUs 2, is connected to a CU 1, with thepriority being set for four DUs 2.

FIG. 39 is a flowchart of information processing by the CUs 1 in thepriority resetting processing of the CUs 1 included in the conferencesystem S.

The control portion 16 of the primary CU reads the unit settinginformation DB from the storage portion 13 of the primary CU (S1071).The control portion 16 of the primary CU references the unit settinginformation DB and compares the number of DUs 2 for which the priorityis set (referred to hereinafter as “number of priority-set units”) andthe set maximum number of speakers of the entire conference system Sthat is set in the primary CU (S1072).

When the number of priority-set units is greater than or equal to theset maximum number of speakers (“Yes” in S1072), the control portion 16of the primary CU turns off, for one unit at a time, the prioritysetting of the currently unconnected DUs (referred to hereinafter asunconnected DUs) 2 among the DUs 2 for which the unit settinginformation is stored in the unit setting information DB (S1073). Theprocessing of turning off the priority settings of the unconnected DUs 2is executed in an order starting from the DUs 2, with the unit settinginformation stored in the unit setting information DB of the CU 1 withthe relative ID of larger numerical value (the CU 1B in the presentembodiment). That is, the processing (renewal of the priority) of thesecondary DUs that are connected to the secondary CU is given precedenceover the processing (renewal of the priority) of the primary DUs thatare connected to the primary CU.

When the number of priority-set units is less than the set maximumnumber of speakers (“No” in S1072), the conference system S ends thepriority resetting processing (S107).

Next, the control portion 16 of the primary CU compares the number ofpriority-set units and the set maximum number of speakers (S1074). Whenthe number of priority-set units is greater than or equal to the setmaximum number of speakers (“Yes” in S1074), the control portion 16 ofthe primary CU checks (specifies) the remaining number of unconnectedDUs 2 (S1075). If there is any unconnected DUs 2 remaining (“Yes” inS1075), the control portion 16 of the primary CU continues theprocessing of turning off the priority settings of the unconnected DUs 2(S1073).

If there is no unconnected DUs 2 remaining (“No” in S1075), the controlportion 16 of the primary CU turns off, for one unit at a time, thepriority settings of the currently connected DUs (referred tohereinafter as “connected DUs”) 2 (S1076). The processing of turning offthe priority settings of the connected DUs 2 is executed in an orderstarting from the DU 2 with the relative ID of larger numerical valueamong the DUs 2 connected to the CU 1 with the relative ID of largernumerical value.

Next, the control portion 16 of the primary CU compares the number ofpriority-set units and the set maximum number of speakers (S1077). Whenthe number of priority-set units is greater than or equal to the setmaximum number of speakers (“Yes” in S1077), the control portion 16 ofthe primary CU continues the processing of turning off the prioritysettings of the connected DUs 2 (S1076).

When the number of priority-set units has become less than the setmaximum number of speakers (“No” in S1074 and “No” in S1077), thecontrol portion 16 of the primary CU renews the unit setting informationstored in the unit setting information DB in the storage portion 13 ofthe primary CU. In conjunction with the renewal of the unit settinginformation stored in the unit setting information DB in the storageportion 13 of the primary CU, the control portion 16 of the secondary CUrenews the unit setting information stored in the unit settinginformation DB in the storage portion 13 of the secondary CU.Consequently, the priority setting of each DU 2 stored in the storageportion 13 of each CU 1 is renewed. The conference system S ends thepriority resetting processing (S107).

The conference system S thus changes the priority settings of the DUs 2automatically when there is a change in the connection state of the CUs1 to each other. In other words, when the new CU count value and the oldCU count value are mismatched, the conference system S renews thepriority setting of each speech-enabled DU 2. Therefore, with theconference system according to the present invention, the abovementionedinconsistent state does not occur. Also, the conference system S makesit unnecessary for the system administrator to perform priority settingin accordance with the connection state of the CUs 1 to each other. Theload of priority resetting by the system administrator is thuslightened.

Also, the priority resetting processing may be of a mode that isexecuted when the number of connected units of secondary CUs isdecreased in the CU connection state check processing, that is, when thenumber of connected units of secondary CUs stored in the storage portion13 of the primary CU (old CU count value) is greater than (mismatchedwith) the newly recognized number of connected units of secondary CUs(new CU count value). That is, for example in the priority resettingprocessing, processing may be performed so that when the number ofconnected units of secondary CUs decreases, the number of DUs 2 forwhich the priority is set is the same before and after the change of thenumber of connected units. Specifically, in the priority resettingprocessing, processing may be performed so that with the priority rightsof the primary DUs stored in the storage portion 13 of the primary CU,the priority ranking of the prior right is raised (or the prioritysetting is turned on) for a portion of the primary DUs.

Also in the priority resetting processing, processing may be performedso that with the priority rights of the primary DUs stored in thestorage portion 13 of the primary CU, the priority ranking of the priorright is lowered (or the priority setting is turned off) for a portionof the primary DUs when an increase of the number of connected units ofsecondary CUs is checked in the CU connection state check processing.That is, in the priority resetting processing, processing may beperformed so that when the number of connected units of secondary CUsstored in the storage portion 13 of the primary CU (old CU count value)is less than (mismatched with) the newly recognized number of connectedunits of secondary CUs (new CU count value), the priority ranking of thepriority right is lowered (or the priority setting is turned off) for aportion of the primary DUs instead of lowering the priority ranking ofthe priority right starting from the secondary DUs as described above.

Running Processing

Next, the conference system S executes the running processing (S4). Withthe exception that the primary CU manages the connection states of thesecondary CU and the secondary DUs, the audio information of thesecondary DUs, etc., the running processing (S4) is the same as therunning processing (FIG. 22) described above. That is, the primary CUrepeatedly transmits and receives a running packet to and from theprimary DUs and repeatedly transmits and receives a running packet toand from the secondary DUs via the secondary CU. In this process, thesecondary CU repeatedly transmits and receives the running packet to andfrom the secondary DUs.

Conference Mode

The conference system S includes conference modes. Each conference modeis information (combination information) specifying a combination of therespective setting contents of the setting items “Override,” “Mic ontrigger (priority set),” and “Mic on trigger (priority not set)” amongthe various setting items that define the operations of the conferencesystem S. In other words, the conference system S specifies thecombination of the respective setting contents of override, mic ontrigger (priority set), and mic on trigger (priority not set) based onthe conference mode. Each of the setting items will be described below.

FIG. 40 is a schematic diagram of an example of the conference modes.

This figure shows that the conference system S includes the threeconference modes of “Free conversation mode,” “Request talk mode,” and“Full remote mode.” The figure shows the combination of the respectivesetting contents of the override, the mic on trigger (priority set), andthe mic on trigger (priority not set) of each conference mode.

The figure shows that, for example, in the case of the conference mode“Free conversation mode,” any of “Off” “On/FIFO,” and “On/LIFO” isselectable as the setting content of the setting item “Override.” Also,the figure shows that, for example, in the case of the conference mode“Request talk mode,” either of “Manual trigger” and “Automatic trigger”is selectable as the setting content of the setting item “Mic on trigger(priority set).” Yet further, the figure shows that, for example, in thecase of the conference mode “Full remote mode,” the setting item “Mic ontrigger (priority not set)” cannot be set. The respective settingcontents of each of the setting items shown in the figure will bedescribed below.

Before selection of the conference mode, the conference system S storesinformation, indicating combinations of information specifying theconference modes shown in FIG. 40 and the setting contents of therespective setting contents, in advance in the storage portion 13 of theCU 1. The conference system S references the storage portion 13 based oninformation specifying the conference mode that is input from theoperating station 4 by operation by the system administrator, etc., thatis, based on the combination information to specify the respectivesetting contents of “Override,” “Mic on trigger (priority set),” and“Mic on trigger (priority not set)” corresponding to the conferencemode. That is, the storage portion 13 stores the combination informationand the information specifying the setting contents of each of thesetting items in association.

The Setting Item “Override”

The override is a setting item related to an assignment mode thatdetermines “On” or “Off” of the override in the assignment of audio slotand audio region to a DU 2 with the request flag added.

The override is processing by which, when a speech request is made (whenthe request flag is added to a running packet) in a state where there isno vacancy in audio slot and audio region, an audio slot and an audioregion are assigned to a DU 2 making the speech request without waitingfor the end of speech at a DU 2 that is already assigned an audio slotand an audio region. The override includes assignment modes when it is“On” and an assignment mode when it is “Off.” When the override is “On,”processing in accordance with one of either of the assignment modes ofFIFO (First In First Out) and LIFO (Last In First Out) is performed inthe override.

FIFO is an assignment mode where the assignment of audio slot and audioregion is removed from a DU 2, which has been permitted speech firstamong the DUs 2, each already assigned an audio slot and an audioregion. In FIFO, the DUs 2 that are respectively assigned an audio slotand an audio region are successively removed of the assignment of audioslot and audio region.

LIFO is an assignment mode where the assignment of audio slot and audioregion is removed from a DU 2, which has been permitted speech lastamong the DUs 2, each already assigned an audio slot and an audioregion. In LIFO, only the DU 2 that was assigned the last vacant audioslot and audio region among the audio slots and audio regions (that waspermitted for speech at the immediately previous timing) is replaced.

On the other hand, the assignment mode when the override is “Off” is anassignment mode where the assignment of audio slot and audio region isremoved from a DU 2 at which speech is ended among the DUs 2, eachalready assigned an audio slot and an audio region. That is, a DU 2 atwhich a speech request is made waits for the end of speech at a DU 2(referred to as “a”) that is already assigned an audio slot and an audioregion and is thereupon assigned the audio slot and the audio regionassigned to the DU 2(a) at which speech is ended. That is, the requestprocessing (FIG. 28) described above is processing that is executed whenthe override is “Off.”

Information (referred to hereinafter as “assignment mode information)that specifies an assignment mode among the plurality of assignmentmodes is stored in association with the combination information in thestorage portion 13. For example, the conference mode “Free conversationmode” is associated with the assignment modes respectively correspondingto the setting contents “Off,” “On/FIFO,” and “On/LIFO” of the settingitem “Override.” The assignment mode information is information includedin the control information described above. That is, for example, if thesetting content “On/FIFO” is selected for the setting item “Override,”the conference system S assigns an audio slot and an audio region to aDU 2, at which a speech request is made, in accordance with theassignment mode where the assignment of audio slot and audio region isremoved successively.

The Setting Item “Mic on Trigger”

The mic on trigger is a mode related to the setting of the trigger foradding the request flag to the running packet (for making a speechrequest), that is, a mode related to the request flag addition mode. Themic on trigger includes the setting item “Mic on trigger (priority set)”for a DU (referred to hereinafter as “priority-set DU”) 2 p for whichthe priority is set and the setting item “Mic on trigger (priority notset)” for a DU (referred to hereinafter as “priority-not-set DU”) 2 nfor which the priority is not set. The mic on trigger is a trigger forturning on the microphone 3 mounted on a DU 2 and includes the twoaddition modes of “Manual trigger” and “Automatic trigger.” With the micon trigger, one of either of the addition modes of “Manual trigger” and“Automatic trigger” is selected.

Information (referred to hereinafter as “addition mode information) thatspecifies an addition mode among the plurality of assignment modes isstored in association with the combination information in the storageportion 13. For example, the conference mode “Request talk mode” isassociated with the addition mode corresponding to the setting content“Manual trigger” of the setting item “Mic on trigger (priority set).”The addition mode information is information included in the controlinformation described above. The addition mode information is stored inassociation with the assignment mode information in the storage portion13.

The Conference Mode “Free Conversation Mode”

The free conversation mode is a conference mode in which the users ofDUs 2, each with an audio slot assigned, is enabled to speak freely. Anaudio slot and an audio region are always assigned to a priority-set DU2 p. To a priority-not-set DU 2 n, an audio slot and an audio region areassigned in accordance with the selected assignment mode. In the freeconversation mode, an audio slot and an audio region are assignedautomatically and therefore a situation of rejection of a speech requestdoes not occur. The operating station 4 is thus not necessarily requiredin the free conversation mode.

In the free conversation mode, one of the three setting contents of“Off,” “On/FIFO,” and “On/LIFO” is selected for the setting item“Override.”

In the free conversation mode, the setting item “Mic on trigger” is setindividually for each DU 2. That is, for example, a DU 2 with which themanual trigger is selected and a DU 2 with which the automatic triggeris selected may coexist.

The Conference Mode “Request Talk Mode”

The request talk mode is a conference mode in which a speech request ismade by a manual trigger at a priority-not-set DU 2 n. An audio slot andan audio region are always assigned to a priority-set DU 2 p. For apriority-not-set DU 2 n, selection between permitting and rejecting aspeech request is made based on a request from the operating station 4.

In the request talk mode, the setting content “Off” cannot be selectedfor the setting item “Override.” That is, in the request talk mode, oneof either “On/FIFO” or “On/LIFO” is selected as the setting content ofthe override.

For the setting item “Mic on trigger” in the request talk mode, only themanual trigger is selected as the setting of a priority-not-set DU 2 n.

The Conference Mode “Full Remote Mode”

The full remote mode is a conference mode in which speech by apriority-not-set DU 2 n becomes enabled by operation from the operatingstation 4. With a priority-set DU 2 p, an audio slot and an audio regionare always assigned. With a priority-not-set DU 2 n, speech is permittedbased on a request from the operating station 4.

In the full remote mode, the setting content “Off” cannot be selectedfor the setting item “Override.” That is, in the full remote mode, oneof either “On/FIFO” or “On/LIFO” is selected as the setting content ofthe override.

For the setting item “Mic on trigger” in the full remote mode, thesetting of the trigger cannot be performed for a priority-not-set DU 2n.

Operations of the Conference System Based on the Conference Mode

Next, operations of the conference system based on the conference modewill be described. The conference system S operates based on theassignment mode of audio slot and audio region for each DU 2 and therequest flag addition mode that are determined in accordance with theconference mode selected from among the plurality of conference modes.

FIG. 41 is a flowchart of information processing in conference modeselection (S200).

The conference mode selection (S200) is executed, for example, betweenthe DU information acquisition processing (FIG. 17 and FIG. 18) and theDU setting processing (FIG. 20 and FIG. 21) in the informationprocessing executed by the conference system S described above.

First, by operation by the system administrator, etc., the operatingstation 4 reads the combination information from the storage portion 13of the CU 1 (primary CU) connected to the operating station 4 and storesthe information in the storage portion 43 (S2001).

Next, the conference mode is selected (S2002). That is, for example, viaa preparation screen to be described below, the operating station 4makes one conference mode be selected from among the free conversationmode (S201), the request talk mode (S202), and the full remote mode(S203) by the system administrator, etc., based on the conferencecontents, etc. The control portion 46 of the operating station 4specifies, from among the plurality of combination information stored inthe storage portion 43, the combination information that is inaccordance with the selected conference mode (S2003). Here, for example,when the conference mode “Free conversation mode” shown in FIG. 40 isselected, the control portion 46 of the operating station 4 makes thedisplay portion 44 display a screen by which the system administrator,etc., makes a selection from among “Off,” “On/FIFO,” and “On/LIFO” asthe setting content of the setting item “Override” for each DU 2.Similarly, the control portion 46 of the operating station 4 makes thedisplay portion 44 display a screen by which the system administrator,etc., make selections from between “Manual trigger” and “Automatictrigger” as the setting contents of the setting items “Mic on trigger(priority set)” and “Mic on trigger (priority not set)” for each DU 2.By the screen displayed on the display portion 44 being operated, theassignment mode of audio slot and audio region for each DU 2 and therequest flag addition mode are determined. The communication portion 41of the operating station 4 transmits the determined assignment mode ofaudio slot and audio region for each DU 2 and request flag addition modeas the specified combination information to the CU 1 (S2004). The CU 1stores the combination information, received from the operating station4, as the unit setting information for each DU 2 in the storage portion13 (in regard to a DU 2 for which the unit setting information is storedalready, the unit setting information stored in the storage portion 13is renewed). Based on the renewed unit setting information, the CU 1executes the above-described DU setting processing (FIGS. 20 and 21) tochange the unit setting of each DU 2. Consequently, the conferencesystem S operates based on the selected conference mode.

When the Conference Mode is “Free Conversation Mode”

As described above, each DU 2 makes a speech request based on theindividually set mic on trigger.

FIG. 42 is a flowchart of information processing by the CU 1 in the freeconversation mode.

First, the control portion 16 of the CU 1 waits for a speech requestfrom the DU 2 (“No” in S2011). When there is a speech request from a DU2 (“Yes” in S2011), the control portion 16 of the CU 1 checks whetherthe DU 2 that made the speech request is a priority-set DU 2 p or apriority-not-set DU 2 n (S2012).

When the DU 2 that made the speech request is a priority-set DU 2 p(“Yes” in S2012), the control portion 16 of the CU 1 assigns apredetermined audio slot and audio region to the priority-set DU 2 p(S2013).

When the DU 2 that made the speech request is a priority-not-set DU 2 n(“No” in S2012), the control portion 16 of the CU 1 checks for a vacancyin audio slot and audio region (S2014).

When there is a vacancy in audio slot and audio region (“Yes” in S2014),the control portion 16 of the CU 1 assigns the vacant audio slot andaudio region to the priority-not-set DU 2 n (S2015).

When there is no vacancy in audio slot and audio region (“No” in S2014),the control portion 16 of the CU 1 checks the override setting contentof the priority-not-set DU 2 n (S2016).

When the override setting content is “On” (“Yes” in S2016), the controlportion 16 of the CU 1 forcibly assigns an audio slot and an audioregion to the priority-not-set DU 2 n (performs override) in accordancewith the setting content of either FIFO or LIFO (S2017).

When the override setting content is “Off” (“No” in S2016), the controlportion 16 of the CU 1 checks for a vacancy in audio slot and audioregion again (S2014). During this time, the priority-not-set DU 2 n isput in a speech waiting state (request waiting state) until an audioslot and an audio region become vacant.

When the Conference Mode is “Request Talk Mode”

As described above, in the request talk mode, the mic on trigger of apriority-not-set DU 2 n is set in advance to the manual mode. The mic ontrigger of a priority-set DU 2 p is set in advance to one of either theautomatic mode or the manual mode.

FIG. 43 is a flowchart of information processing by the CU 1 in therequest talk mode.

The control portion 16 of the CU 1 waits for a speech request from theDU 2 (“No” in S2021). When there is a speech request from a DU 2 (“Yes”in S2021), the control portion 16 of the CU 1 checks whether the DU 2that made the speech request is a priority-set DU 2 p or apriority-not-set DU 2 n (S2022).

When the DU 2 that made the speech request is a priority-set DU 2 p(“Yes” in S2022), the control portion 16 of the CU 1 assigns apredetermined audio slot and audio region to the priority-set DU 2 p(S2023).

When the DU 2 that made the speech request is a priority-not-set DU 2 n(“No” in S2022), the control portion 16 of the CU 1 puts thepriority-not-set DU 2 n on the speech request list (S2024). The speechrequest list is, for example, a table in which the DUs 2 that made aspeech request are listed in the order of request.

A priority-not-set DU 2 n listed in the speech request list is put inthe request waiting state until one of either permission or rejection ofthe speech request is selected. Permission or rejection of the speechrequest selected, for example, by operation of the operating station 4by the chairman, etc.

When permission of the speech request is selected (“Yes” in S2025), thecontrol portion 16 of the CU 1 forcibly assigns an audio slot and anaudio region to the priority-not-set DU 2 n in accordance with thesetting content of either FIFO or LIFO (S2026). At this point, thecontrol portion 16 of the CU 1 deletes the priority-not-set DU 2 n, ofwhich the speech request was permitted, from the speech request list(S2027).

When the speech request is rejected (“No” in S2025), the control portion16 of the CU 1 deletes the priority-not-set DU 2 n from the speechrequest list (S2028).

When the Conference Mode is “Full Remote Mode”

As described above, in the full remote mode, the mic on trigger of apriority-not-set DU 2 n is not set to any setting (is off). That is, apriority-not-set DU 2 n cannot make a speech request. The mic on triggerof a priority-set DU 2 p is set in advance to one of either theautomatic mode or the manual mode.

FIG. 44 is a flowchart of information processing by the CU 1 in the fullremote mode.

First, the control portion 16 of the CU 1 waits for a request that iseither a speech request from a DU 2 or a request from the operatingstation 4 (“No” in S2031). When there is a request (“Yes” in S2031), thecontrol portion 16 of the CU 1 checks whether the request is a speechrequest from a DU 2 or a request from the operating station 4 (S2032).As mentioned above, a speech request is only made by a priority-set DU 2p. A request from the operating station 4 is made for a priority-not-setDU 2 n.

When the request is a speech request (“Speech request” in S2032), thecontrol portion 16 of the CU 1 assigns a predetermined audio slot andaudio region to the priority-set DU 2 p that made the speech request(S2033).

When the request is a request from the operating station 4 (“Stationoperation” in S2032), the control portion 16 of the CU 1 checks for avacancy in audio slot and audio region (S2034).

When there is a vacancy in audio slot and audio region (“Yes” in S2034),the control portion 16 of the CU 1 assigns the vacant audio slot andaudio region to the priority-not-set DU 2 n, for which speech isrequested by the operating station 4 (S2035).

When there is no vacancy in audio slot and audio region (“No” in S2034),the control portion 16 of the CU 1 forcibly assigns an audio slot and anaudio region to the priority-not-set DU 2 n in accordance with thesetting content of either FIFO or LIFO (S2036).

Summary of the Conference Modes

The conference system S thus includes a plurality of conference modes,which are selectable and in which the setting contents of the mic ontrigger mode and the override mode are combined. Therefore, for example,when a person, who is an employee in a general affairs department, etc.,and performs preparation of operation setting of the conference system Simmediately before the start of a conference, can suitably select theoptimal conference mode from among the plurality of conference modes andthereby readily perform preparation of the operation setting of theconference system S.

Input Screens of the Operating Station

The various control information for controlling the operations of theconference system S is input, for example, via input screens displayedon the display portion 44 of the operating station 4 and stored in thestorage portion 13 of the CU 1. The input screens are screens used bythe system administrator, etc., in inputting and changing the controlinformation. That is, for example, the input screens are screens forinputting settings of the CU 1 and the DUs 2. As mentioned above, thecontrol information includes, for example, information related to systemsettings of the conference system S, information related to thepriority, the speech request list, etc. The control portion 46 of theoperating station 4 reads control information corresponding to eachinput screen from the storage portion 13 of the CU 1 and makes theinformation be displayed on the display portion 44.

The input screens include, for example, a conference system initialsetting screen (referred to hereinafter as “initial screen”), aconference preparation screen (referred to hereinafter as “preparationscreen”), and a conference progress screen (referred to hereinafter as“progress screen”). One of the input screens is selected by the controlportion 46 of the operating station 4 based on predetermined conditionsto be described below. That is, for example, the control portion 46judges whether or not the predetermined conditions are met and, based onthe judgment result, selects the input screen to be displayed on thedisplay portion 44 from among the initial screen, the preparationscreen, and the progress screen. The predetermined conditions are, forexample, states of physical/communicational connection between the CU 1and the DUs 2 (whether or not there is connection, etc.), completion ofsetting of a specific item, occurrence of an abnormality in theconnection state of the DUs 2, connection state of a specific DU (forexample, an interpreter unit, etc.), etc. That is, for example, thecontrol portion 46 selects the input screen to be displayed on thedisplay portion 44 based on a result of judging whether or not specificcontrol information, among the plurality of control information, isstored in the storage portion 13 of the CU 1, a result of judgingwhether or not a DU 2 is connected to the unit connection portion 12 b,a result of judging whether or not a specific DU 2, among a plurality ofDUs 2, is connected to the unit connection portion 12 b, a result ofjudging whether or not a connection abnormality of the DUs 2 connectedto the unit connection portion 12 b is occurring, etc.

FIG. 45 is a schematic diagram of a selection screen for input screensthat is displayed on the display portion 44 of the operating station 4included in the conference system S.

In the figure, an item that can be selected is indicated by solid linesand an item that cannot be selected is indicated by broken lines.

When the conference system S is started, the selection screen isdisplayed on the display portion 44 of the operating station 4. Theselection screen is, for example, a screen by which a systemadministrator or a person performing preparation of the operationsetting of the conference system S, etc., performs selection of a screenfrom among the initial screen, the preparation screen, and the progressscreen.

The input screens that are displayed as being selectable in theselection screen change, for example, in accordance with thecommunication state of the CU 1 and the DUs 2. That is, for example,when the CU 1 and the DUs 2 are communication-disabled, only the initialscreen is selectable among the input screens displayed in the selectionscreen. That the CU 1 and the DUs 2 are communication-disabled refers,for example, to a state where the DUs 2 are not connected to the CU 1,etc. When the CU 1 and the DUs 2 are communication-enabled, thepreparation screen and the progress screen are selectable among theinput screens displayed in the selection screen. That the CU 1 and theDUs 2 are communication-enabled refers, for example, to a state wherethe DUs 2 are connected to the CU 1, etc. The input screens that aredisplayed as being selectable in the selection screen are determined bythe control portion 46 of the operating station 4. By the selectableinput screens thus changing in accordance with predetermined conditions,selection of an input screen by a person performing input of informationis made easy and erroneous operations and erroneous inputs such that theset contents become inconsistent with each other, etc., are reducedbecause various settings based on the predetermined conditions can beperformed.

With the selection screen in the present embodiment, the selectableinput screens may change, for example, in accordance with authenticationinformation input in a login screen, etc.

Also, the selection screen may display a screen, for example, in whichinformation related to the priority setting is input when the CU 1 and aplurality of DUs 2 are communication-enabled.

Further, the selection screen may display a screen, for example, inwhich communication information is input in the initial screen when theCU 1 and a plurality of DUs 2 are communication-disabled.

Yet further, the selection screen may be of mode where, when a DUcorresponding to a specific application, such as an interpreter unit,etc., is connected to the CU 1, a screen is displayed in whichinformation related to settings corresponding to the specificapplication are input.

Yet further, the input screens selectable in the selection screen arenot restricted to those of the present embodiment. That is, for example,the input screens selectable in the selection screen may include otherinput screens, such as a maintenance screen, etc.

Initial Screen

FIG. 46 is a schematic diagram of the initial screen.

The initial screen is a screen by which, for example, the systemadministrator inputs/changes settings of the conference system S. Theinformation displayed in the initial screen is information related tosystem settings of the conference system S, for example, information forinitial setting of the conference system S, such as communicationinformation, such as a subnet mask, etc., used by the CU 1 to specifyDUs 2 (used for the CU 1 and the DUs 2 to communicate), informationrelated to firmware, terminal setting information of the CU 1, etc.

By completion of input of the information in the initial screen, the CU1 and the DUs 2 become communication-enabled. By completion of input ofthe information in the initial screen, the preparation screen and theprogress screen become selectable in the selection screen.

Preparation Screen

FIG. 47 is a schematic diagram of the preparation screen.

The preparation screen is a screen by which, for example, a personperforming preparation of the operation setting of the conference systemS inputs settings of the respective DUs 2. The information displayed inthe preparation screen is the unit setting information of the respectiveDUs 2, for example, information related to priority settings,information related to mic on trigger settings, the light emittingcolors of the light emitting portions 28 of the DUs 2 and othernotification information, etc. The information is displayed in thepreparation screen, for example, in association with the relative IDs ofthe DUs 2.

The unit setting information displayed in the preparation screen, forexample, the unit setting information of DUs 2 connected to the CU 1 inthe past is information stored in the unit setting information DB. Onthe other hand, the unit setting information of DUs 2 that are newlyconnected to the CU 1 includes settings (initial values) of the DUs 2 atthe time of shipment as described above.

FIG. 48 is a schematic diagram of the preparation screen after input ofinformation.

In the figure, information newly input from the preparation screen shownin FIG. 47 is indicated by underlining.

Progress Screen

FIG. 49 is a schematic diagram of the progress screen.

The progress screen is a screen by which, for example, a personoverseeing the progress of a conference, such as the chairman, etc.,inputs information for controlling the operations of the respective DUs2. The information displayed in the progress screen is informationrelated to the control of the respective DUs 2, for example, informationrelated to the speech request list and the conference mode, etc.

The progress screen is used by the chairman, etc., for example, when theabove-described conference mode of request talk mode or full remote modeis selected. For example, the operating station 4 displays the speechrequest list in the progress screen to enable the chairman to selectbetween permitting and rejecting a speech request in the progressscreen.

Summary of the Input Screen

Thus, with the conference system S, one input screen is selected by thecontrol portion 46 of the operating station 4 based on predeterminedconditions. Therefore, the conference system S avoids mutualinconsistency of the input setting contents. That is, the conferencesystem according to the present embodiment realizes reliable settingwork with a simple configuration.

The respective input screens in the present information may differ inGUI (Graphic User Interface) display mode in accordance with the itemsdisplayed on the screens. That is, for example, the conference system Smay display the initial screen in an accordion form, the preparationscreen in a wizard form, and the progress screen in a tab form.

Also, the respective input screens in the present invention may differin the items displayed on the display portion 44 in accordance with therights of the person operating the operating station 4. Consequently,input or change of information that is in disagreement with the rightsof the person operating the operating station 4 is prevented.

Summary

In the conference system S according to the embodiment described above,the conference system S periodically transmits packets, each including acounter flag, from the CU 1 to the DUs 2 to renew the information storedin the database associating the relative IDs and the absolute IDs. Withthe conference system S, even if a connection abnormality occurs in a DU2 and a change in relative ID occurs, the association of the relativeIDs and the absolute IDs is renewed and therefore discrepancy ofinformation, such as the audio information, etc., before and after thechange of connection state of the DUs 2 does not occur. That is, theconference system according to the present invention is capable ofreliably managing the connection state of the CU and the DUs 2 andcontinuously acquiring information from the DUs when a connectionabnormality occurs.

Also, in the conference system according to the embodiment describedabove, when connection or disconnection of CUs 1 to or from each otheroccurs, the conference system S automatically changes the prioritysettings. Therefore, with the conference system according to the presentinvention, the inconsistent state described above does not occur. Also,the conference system according to the present invention makes itunnecessary for the system administrator to perform the setting of thepriority in accordance with the connection state of CUs to each other.The conference system according to the present invention thus lightensthe load of priority resetting by the system administrator.

Further, in the conference system according to the embodiment describedabove, the conference system S fetches speech requests from the DUs 2 byperiodic processing of the request flag and makes the CU 1 transmitcommands in accordance with the vacancy of audio slot and audio region.That is, the conference system S does not transmit a command from a DU 2to the CU 1 on each speech request. Therefore, with the conferencesystem according to the present invention, an excessive informationprocessing load is not received even when speech requests are made froma plurality of DUs 2 at once. Consequently, the conference system Saccording to the present invention does not require a high processingability in comparison to a system where a DU receives a command from aCU on each speech request.

Yet further, in the conference system according to the embodimentdescribed above, a DU 2 that makes a speech request is automatically putin the request waiting state if there is no vacancy in audio slot andaudio region. The conference system according to the present inventionis thus not required to answer all speech requests by software and theinformation processing load in terms of software is lightened.

Yet further, in the conference system according to the embodimentdescribed above, the conference system S has one input screen selectedby the control portion 46 of the operating station 4 based onpredetermined conditions. Therefore, the conference system according tothe present invention is capable of avoiding mutual inconsistency of thesetting contents set by a person performing input of information. Thatis, the conference system according to the present invention realizesreliable setting work with a simple configuration.

Yet further, in the conference system according to the embodimentdescribed above, the conference system S makes a conference mode, whichis associated with the override and the mic on trigger, be selected toset the assignment mode of audio slot and audio region for each DU 2 andthe request flag addition mode. Therefore, for example, even a person,who is not a person having expert knowledge, such as an operator, etc.,can suitably select, from among the plurality of conference modes, theconference mode, which is optimal in terms of the conference contents,constitution of participants, etc., and thereby readily performpreparation of the operation setting of the conference system S. Thatis, the conference system according to the present invention isexcellent in convenience of setting work.

Summary of the Conference System According to the Present Invention

Features of the conference system according to the present inventiondescribed above are summarized below.

(Feature 1)

A conference system comprising:

a control unit (CU 1); and

a discussion unit (DU 2), wherein

the discussion unit is connected via a communication line to the controlunit,

the control unit repeatedly transmits and receives a running packet toand from the discussion unit,

the running packet includes a counter flag,

the control unit includes

-   -   a CU communication portion (communication portion 11),    -   a CU storage portion (storage portion 13), and    -   a CU control portion (control portion 16),

the discussion unit includes

-   -   a DU control portion (control portion 26) and    -   a DU communication portion (communication portion 21),

the CU control portion resets a count value of the counter flag includedin the running packet transmitted to the discussion unit,

the CU communication portion transmits the running packet to thediscussion unit,

the DU control portion increments the count value of the counter flag,

the DU communication portion transmits the running packet, whichincludes the counter flag with the incremented count value, to thecontrol unit,

the CU storage portion stores the count value of the counter flagincluded in the running packet received by the control unit from thediscussion unit, and

each time the control unit receives the running packet from thediscussion unit, the CU control portion compares the count value storedin the CU storage portion and the count value of the counter flagincluded in the running packet received by the control unit from thediscussion unit.

(Feature 2)

The conference system according to feature 1, where, when the countvalue stored in the CU storage portion and the count value of thecounter flag included in the running packet received by the control unitfrom the discussion unit are mismatched, the CU control portion renewsthe count value stored in the CU storage portion with the count value ofthe counter flag included in the running packet.

(Feature 3)

The conference system according to feature 1, where

the control unit is connected to a plurality of the discussion units,

the CU storage portion stores, in association,

a relative ID of each discussion unit that is numbered based on thecount value of the counter flag included in the running packet receivedby the control unit from the discussion units, and

an absolute ID of each discussion unit, and,

when the count value stored in the CU storage portion and the countvalue of the counter flag included in the running packet received by thecontrol unit from the discussion units are mismatched, the CU controlportion renews the association of the relative IDs and the absolute IDs.

(Feature 4)

The conference system according to feature 3, where

the control unit includes

a CU connection portion (unit connection portion 12 b) and

the discussion units are connected to the CU connection portion.

(Feature 5)

The conference system according to feature 4, where

the CU connection portion includes a plurality of connection terminals.

(Feature 6)

The conference system according to feature 5, where, each time thecontrol unit receives the running packet from the discussion units, theCU control portion compares a transmission connection terminal, which,among the plurality of connection terminals, transmitted the runningpacket from the control unit to the discussion units, and a receptionconnection terminal, which, among the plurality of connection terminals,is the terminal by which the control unit received the running packetfrom the discussion units, to judge a connection mode of the controlunit and the discussion units.

(Feature 7)

The conference system according to feature 6, where

the CU control portion

judges the connection mode to be a daisy chain connection mode when thetransmission connection terminal and the reception connection terminalare matched, and

judges the connection mode to be a ring connection mode when thetransmission connection terminal and the reception connection terminalare not matched, and

the judged connection mode is stored in the CU storage portion inassociation with the absolute IDs of the discussion units.

(Feature 8)

The conference system according to feature 7, where,

when the connection mode stored in the CU storage portion and the judgedconnection mode differ, the CU control portion renews the connectionmode stored in the CU storage portion with the judged connection mode.

(Feature 9)

The conference system according to feature 2, where

the control unit is connected to a plurality of the discussion units,

the CU storage portion stores, in association,

a relative ID of each discussion unit that is numbered based on thecount value of the counter flag included in the running packet receivedby the control unit from the discussion units, and

an absolute ID of each discussion unit,

the CU communication portion transmits a setting packet, carrying a unitsetting command, to perform setting of the discussion units, to thediscussion units, and

the setting packet has the absolute IDs of the discussion units as thetransmission destinations of the setting packet.

The invention claimed is:
 1. A conference system comprising: a controlunit; and a discussion unit, wherein the discussion unit is connectedvia a communication line to the control unit, the control unitrepeatedly transmits and receives a running packet to and from thediscussion unit, the running packet includes a counter flag, the controlunit comprises: a CU communication portion, a CU storage portion, and aCU control portion, the discussion unit comprises: a DU control portion,and a DU communication portion, the CU control portion resets a countvalue of the counter flag included in the running packet transmitted tothe discussion unit, the CU communication portion transmits the runningpacket to the discussion unit, the DU control portion increments thecount value of the counter flag, the DU communication portion transmitsthe running packet, which includes the counter flag with the incrementedcount value, to the control unit, the CU storage portion stores thecount value of the counter flag included in the running packet receivedby the control unit from the discussion unit, and each time the controlunit receives the running packet from the discussion unit, the CUcontrol portion compares the count value stored in the CU storageportion and the count value of the counter flag included in the runningpacket received by the control unit from the discussion unit.
 2. Theconference system according to claim 1, wherein, when the count valuestored in the CU storage portion and the count value of the counter flagincluded in the running packet received by the control unit from thediscussion unit are mismatched, the CU control portion renews the countvalue stored in the CU storage portion with the count value of thecounter flag included in the running packet.
 3. The conference systemaccording to claim 2, wherein the control unit is connected to aplurality of the discussion units, the CU storage portion stores, inassociation, a relative ID of each discussion unit that is numberedbased on the count value of the counter flag included in the runningpacket received by the control unit from the discussion units, and anabsolute ID of each discussion unit, the CU communication portiontransmits a setting packet, carrying a unit setting command, to performsetting of the discussion units, to the discussion units, and thesetting packet includes the absolute IDs of the discussion units as thetransmission destinations of the setting packet.
 4. The conferencesystem according to claim 1, wherein the control unit is connected to aplurality of the discussion units, the CU storage portion stores, inassociation, a relative ID of each discussion unit that is numberedbased on the count value of the counter flag included in the runningpacket received by the control unit from the discussion units, and anabsolute ID of each discussion unit, and, when the count value stored inthe CU storage portion and the count value of the counter flag includedin the running packet received by the control unit from the discussionunits are mismatched, the CU control portion renews the association ofthe relative IDs and the absolute IDs.
 5. The conference systemaccording to claim 4, wherein the control unit comprises: a CUconnection portion, and the discussion units are connected to the CUconnection portion.
 6. The conference system according to claim 5,wherein the CU connection portion includes a plurality of connectionterminals.
 7. The conference system according to claim 6, wherein, eachtime the control unit receives the running packet from the discussionunits, the CU control portion compares a transmission connectionterminal, which, among the plurality of connection terminals,transmitted the running packet from the control unit to the discussionunits, and a reception connection terminal, which, among the pluralityof connection terminals, is the terminal by which the control unitreceived the running packet from the discussion units, to judge aconnection mode of the control unit and the discussion units.
 8. Theconference system according to claim 7, wherein the CU control portionjudges the connection mode to be a daisy chain connection mode when thetransmission connection terminal and the reception connection terminalare matched, and judges the connection mode to be a ring connection modewhen the transmission connection terminal and the reception connectionterminal are not matched, and the judged connection mode is stored inthe CU storage portion in association with the absolute IDs of thediscussion units.
 9. The conference system according to claim 8,wherein, when the connection mode stored in the CU storage portion andthe judged connection mode differ, the CU control portion renews theconnection mode stored in the CU storage portion with the judgedconnection mode.